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BIL using our bedroom for intimate purposes

481 replies

WhatTheMirrorSaw · 03/08/2026 16:58

We arrived home from holiday last night. BIL has kindly been cat-sitting for us, popping in twice a day, but not sleeping here overnight. This is important.

This afternoon, I've been sorting out a few things in our room. The sun was shining in, and as it hit the mirror I could clearly see strange marks - handprints, quite high up, and what I think is a willy mark at hip height. They are quite noticeable, so I'm sure they weren't here before we went away.

I suspect BIL has been entertaining himself in our bedroom, either alone or with a partner. He's single and the thought of him bringing a hook-up into our bedroom makes me feel ill.

I've changed the sheets (just in case his activities culminated in our bed), but I don't know if I can bear the thought of him cat-sitting for us again if he does this. But DH will think it's strange if we don't have him back, and DCat has never been to a cattery.

Is there a way I can subtley dissuade him from using our home in this way, without offending him?

I've added photos, but they aren't very good because my phone doesn't seem to focus on the mirror surface.

BIL using our bedroom for intimate purposes
BIL using our bedroom for intimate purposes
Sensitive content
BIL using our bedroom for intimate purposes
OP posts:
Thread gallery
7
GreatUserName · 04/08/2026 09:21

So the saga continues!

Willy or won't he confess to nefarious bedroom shenanigans??

ParsleySageToiletDuckAndBinBags · 04/08/2026 09:22

Is your BIL quite a young man? I think it would be very sad if he felt the need to be down, if you confront him about this. Does he live near you, or is your home in a new town for him? Maybe they have very different cultures where he comes from.

I'd at least give him three more opportunities to cat-sit for you - to see if he attempts the M, the C, and the A - before reaching a firm conclusion and making any accusations.

ParsleySageToiletDuckAndBinBags · 04/08/2026 09:32

Tryanalogue · 04/08/2026 09:16

That’s a bit of a damp squidmark.

At least he wasn't facing the other way when writhing around in the nuddy and pushing up against the mirror - a damp skidmark would have been even worse.

ParsleySageToiletDuckAndBinBags · 04/08/2026 09:52

Calliopespa · 04/08/2026 01:07

In fairness, sometimes there are no words ...

Yes, this goes waaaaaay beyond merely awkward, if OP's suspicions are correct.

"Did you open my box of posh chocolates that were on the side and scoff the lot yourself?"
"Did you buy a premium blockbuster film and charge it to our YouTube account?"
"Did you borrow our car without asking and take it to do your weekly shop?"

........."Did you take all your clothes off in our bedroom, make sweaty love to our mirror, smooshing your slimy willy and goolies against it whilst in the throes of passion, and leave a human slug trail all across the surface?"

WhatTheMirrorSaw · 04/08/2026 09:53

LadyBeatriceBeaHiggins · 04/08/2026 00:25

The willy aspect is a wet flop @WhatTheMirrorSaw

Based on these photographs alone, it is not possible to identify the exact cause with certainty, but the marks do have characteristics that make some explanations more likely than others.

General observations

The surface appears to be a mirror viewed under strong directional light. The white areas are not sharply defined scratches or chips; instead they appear as films, smears, or residue sitting on the surface, visible because the light is reflecting at a shallow angle.

The marks have:

  • Diffuse, cloudy edges rather than crisp boundaries.
  • Curved and elongated shapes.
  • No obvious cracking pattern.
  • No radial fractures that would suggest impact damage.
  • No evidence that the reflective backing has failed (which usually produces black or permanently transparent spots).

Likely causes

Hand or finger oils (Most likely)

The second image especially resembles a partial palm or finger contact that has dried and become visible under grazing light.
Human skin leaves:

  • oils
  • sweat
  • salts

These residues often become almost invisible until sunlight or a bright LED strikes the mirror at an angle.
Probability: High

Cleaning residue

Another very common explanation is:

  • glass cleaner allowed to dry
  • soap residue
  • detergent
  • microfiber cloth residue
  • hard-water minerals

These frequently produce cloudy patches exactly like those shown.
Probability: High

Condensation marks

If someone touched the mirror while it was damp (for example after a shower), minerals from skin oils can remain after the moisture evaporates.
Repeated condensation can make these marks progressively more noticeable.
Probability: Moderately high

Cosmetic or aerosol deposits

Products such as:

  • hairspray
  • deodorant
  • perfume
  • furniture polish
  • air freshener

can settle on nearby mirrors.
These deposits are often uneven and create cloudy shapes.
Probability: Moderate

Transfer from another object

The elongated mark in image three could be from something soft resting against the mirror, such as:

  • clothing
  • towel
  • rubber item
  • packaging

Pressure can transfer residue without leaving sharp edges.
Probability: Moderate

The third image

The third photograph is the most interesting.
It shows several parallel streaks with a wider translucent area. That pattern is consistent with something being wiped across the surface while a residue remained behind.
Examples include:

  • wiping with a damp cloth that contained detergent
  • wiping over greasy fingerprints
  • wiping before the cleaner had evaporated

The streaks are much more characteristic of a cleaning action than an impact.

Edited

Is that ChatGPT's explanation of where the marks came from? It's very interesting but isn't AI just trained on what's already floating around on the Internet? Maybe there just aren't many willy marks on mirrors for it to be trained on?

OP posts:
WhatTheMirrorSaw · 04/08/2026 09:56

NotMeAtAll · 04/08/2026 02:05

OP, do you normally fantasise about your BIL writhing around your bedroom while oiled up?

No, never! 😮

OP posts:
Tryanalogue · 04/08/2026 09:57

“The zizi of the ‘uman male leaves a distinct impression on the surface of un miroir.”

BIL using our bedroom for intimate purposes
MargoLeadbetterisQueen · 04/08/2026 09:57

@WhatTheMirrorSaw, yes those AI generated posts are really annoying, imo.
You know full well it was the cat and a hotdog.

SnowFrogJelly · 04/08/2026 09:59

A Willy mark?! 😂

MargoLeadbetterisQueen · 04/08/2026 10:02

WhatTheMirrorSaw · 04/08/2026 09:56

No, never! 😮

Mmm, interesting... perhaps something to work through with a counsellor?

HoppingPavlova · 04/08/2026 10:09

You are a better person than me, as I can see neither hand print or willy print. Just looks like smudges and your pareidolia has run wild.

WhatTheMirrorSaw · 04/08/2026 10:12

Random321 · 04/08/2026 00:44

It's a real waste of a good thread if you don't share your suspicions with DH & BIL and report back!

Ha ha yes, I'm sure that would be entertaining! But I've decided not to mention the marks to either of them as the ramifications would be too much.

OP posts:
MargoLeadbetterisQueen · 04/08/2026 10:14

WhatTheMirrorSaw · 04/08/2026 10:12

Ha ha yes, I'm sure that would be entertaining! But I've decided not to mention the marks to either of them as the ramifications would be too much.

Of course. It's just an entertaining thread on MN.
Nothing to pursue.

WhatTheMirrorSaw · 04/08/2026 10:14

rwalker · 04/08/2026 03:31

Some one single with the run of an empty house
of hell bring someone back for a shag if he has the opportunity don’t be so naive

Our house is very nice! Much nicer than BIL's bachelor pad, in my view.

OP posts:
MargoLeadbetterisQueen · 04/08/2026 10:15

WhatTheMirrorSaw · 04/08/2026 10:14

Our house is very nice! Much nicer than BIL's bachelor pad, in my view.

He may think his place is nicer.

WhatTheMirrorSaw · 04/08/2026 10:15

LarkspurBlues · 04/08/2026 04:46

If it’s the picture I think, then you’re imagining he has gigantic balls and a spindly dick like ET’s finger. Yes?

Er, no....I think you must be looking at a hand print.

The willy one is the long thick smudge.

OP posts:
PinkEasterbunny · 04/08/2026 10:15

I'm in two minds whether or not to mention it to DH at all. He's quite protective of his DB, and historically he's been very reluctant to say anything that might upset his family. The most likely outcome is that he'll be irritated at me for putting him in an awkward position.

Are you STILL not going to mention it to your DH, even if you don't plan to pursue it with BIL?

WhatTheMirrorSaw · 04/08/2026 10:17

CatLandOffTheA3 · 04/08/2026 08:26

Clean the mirror and say and do nothing. Next time, strip your bed before you go. You need a cat sitter in the future right? Just leave it.

Yes, this is what I'll do, I think

OP posts:
WhatTheMirrorSaw · 04/08/2026 10:20

ParsleySageToiletDuckAndBinBags · 04/08/2026 09:22

Is your BIL quite a young man? I think it would be very sad if he felt the need to be down, if you confront him about this. Does he live near you, or is your home in a new town for him? Maybe they have very different cultures where he comes from.

I'd at least give him three more opportunities to cat-sit for you - to see if he attempts the M, the C, and the A - before reaching a firm conclusion and making any accusations.

What does M, C and A mean? Perhaps I shouldn't ask!

BIL is 38. He lives near us. It is a new town for him, but not a new country, and the culture is the same as where he and DH grew up!

OP posts:
WhatTheMirrorSaw · 04/08/2026 10:25

PinkEasterbunny · 04/08/2026 10:15

I'm in two minds whether or not to mention it to DH at all. He's quite protective of his DB, and historically he's been very reluctant to say anything that might upset his family. The most likely outcome is that he'll be irritated at me for putting him in an awkward position.

Are you STILL not going to mention it to your DH, even if you don't plan to pursue it with BIL?

No, I can't bring myself to mention it to DH. I would if it were anyone but his brother, but no matter how politely I phrase it there's no way I can tell him without implying that his bro is a wanker who has betrayed our trust and defiled our bedroom.

Anyway, I've cleaned the mirror now!

OP posts:
WhatTheMirrorSaw · 04/08/2026 10:27

Thanks for your help everyone! I won't mention it to DH or BIL (sorry!) and will continue to ask BIL to cat sit, but I will:

  • install a lock on our bedroom door
  • install a kitty cam on the stairs and point it out to BIL
OP posts:
CypressGrove · 04/08/2026 10:28

WhatTheMirrorSaw · 04/08/2026 10:25

No, I can't bring myself to mention it to DH. I would if it were anyone but his brother, but no matter how politely I phrase it there's no way I can tell him without implying that his bro is a wanker who has betrayed our trust and defiled our bedroom.

Anyway, I've cleaned the mirror now!

Yeah I don't suggest you tell your husband you saw some smears on your mirror and started picturing his brother's naked body thrusting against the mirror.

Anyusernamewilldo8963 · 04/08/2026 10:28

WhatTheMirrorSaw · 04/08/2026 10:20

What does M, C and A mean? Perhaps I shouldn't ask!

BIL is 38. He lives near us. It is a new town for him, but not a new country, and the culture is the same as where he and DH grew up!

Y.M.C.A

tomato22 · 04/08/2026 10:31

DeathBanana · 03/08/2026 18:03

Is there a gap on top of your wardrobe? Could he have been reaching up to get the cat, steadying himself, when unfortunately his trousers and pants slipped down just as he got hold of the cat so he couldn’t catch them before they fell??

😂 😂

ScaredButUnavoidable · 04/08/2026 11:00

I find it odd that you wouldn’t mention it to your DH.

If I found Willy marks on my mirror and I thought his brother had been the one to have caused them my DH would be the first one I’d tell.

Why are you nervous/scared of your DH’s reaction?

What are these “ramifications” that you think you need to avoid by keeping quiet?

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