BIL losing temper whilst staying for weekend

[Theeora]

My sister has recently become engaged to a man I just don't like. I'll be honest.

I live with my parents as I am trying to get on the property ladder this summer. They live remotely in a nice but compact cottage.

This morning they were planning on going for a long walk but my sister asked to adjust plans for very warm weather which dog may not tolerate.

On the drive way I overheard them arguing, BIL said something to the effect of "well, I think the dog is underwalked". My sister told him "how dare you, say it again if you really believe that". BIL did. Ended up with him storming off to their bedroom and SLAMMING the door.

Just to note, our 7 yo is the best looked after dog in the UK. The lengths we go to to look after him are both ridiculous and indulgant. Sure, when BIL is here for the odd weekend the family dog gets walked at random times but never fails to get 2 walks (on top of everything else). BIL and sister often include the dog in walks so the rest of us just work the dog's schedule around that. Dog is also getting on in age so can't walk 10 miles consecutively. Needs to rest after strenuous activity. How dare he imply I'm basically abusing my beloved dog. We live in the Lake District.

Did he act inappropriately re door slamming. I was in kitchen making cookies for the pair and didn't know where to look. Reminds me of a traumatic childhood,lots of arguing between parents (mum and dad have mellowed with age).

Added to the list of red flags

I think your dog is your world and you're very sensitive to implied criticism so this one incident in and of itself doesn't feel like a red flag. The part of your op that interests me is the final sentence. What other red flags have there been?

It's always interesting how your background / previous experiences affect your response to events.

To me, the red flag in the original argument was how the sister escalated it, by overreacting to a fairly minor comment about a dog being walked.

What other red flags have there been?

So the second most recent red flag:

Sister had come up to help with a large house project a couple of months ago. One of those situations where you know the next 48 hours is just going to be a pain in the arse.

Mid activity, we hear a big gasp/"oh no" from the kitchen, said by sis. BIL has had a very minor injury and is in public crying. Sis of course rushes back to London leaving us in the lurch. I had x2 the amount of work to do.

BIL had tried to ring everyone staying with us but we were all stuck in with the job and didnt have phones to hand (we were in garden). Heard him say "ffs, your family is always so bloody hard to reach". We have signal that goes in and out/slow wifi so I'm used to not being attached to phone right now. Don't even bother with netflic anymore. Apparently BIL said he just wanted to hear sister's voice instead of getting in an ambulance/uber. Gross.

The bit that got me was BIL had managed to speak to dad (who hadn't passed on msg in time) without crying. On come the crocodile tears when speaking to sis. It transpires BIL had texted "fuck you" to my sis whilst he was in the middle of trying to contact us.

I do wonder if it's a case of you not liking BIL so anything he does annoys you?

I can totally see how I might hold it together on the phone with a father-in-law, but finally cry when speaking to a partner (without that being switching on 'crocodile tears').

You don't like him and that's ok. You don't need to come up with justifications or tenuous reasons as to why. He rubs you up the wrong way. People will. That's life

Yes, to me, the fact that he behaved like this (performance anger) is the red flag issue.

However, none of us have seen the full picture over time of how he behaves. OP has been able to see a lot more than we have.

And if you don’t believe the story, then why use your time commenting on it?

My daughter’s STBXH behaved in exactly this way many times when he was her fiancé. We tried to talk with DD and him over their engagement period, and I was overjoyed when they split up. Unfortunately DD was emotionally pressured by his sister and mother to return, as he was ‘distraught’ that she’d gone. They got back together, and now years later it’s all in shreds with the kids involved as well. C’est la fucking vie eh?

Seeing this all play out in front of you is painful, and like some PPs I too had a shit childhood because of my parents constant fighting and shouting. My DBro followed in father’s footsteps with unreasonable anger too. Once again, kids, divorce, etc. So awful…

The title of your post indicates your annoyed they were arguing at your parents home *as guests) however all of your replies indicate you're outraged he dared to criticise your care for the dog. Which is bothering you?
From your BILs poverty he knows that each time he visits him and his sister walk the dog who presumably is willing. He doesn't know you're everyday schedule. He gave an opinion. Your sister didn't enlighten him, she challenged him in zn aggressive style and he accepted! This escalated things so he removed himself from the situation. I'm guessing they slept together, ate together znd at some stage drove home together after this event. No significant harm done.
The dog continues to get cared for well and loved.
It's over. Let it go.

You all sound like a bag of mixed nuts tbh.

So as long as I argue with someone in my/my family's home that's OK? The sisters rather ominous 'you dare say that again'... is ok because its her family home? Agree with pp re the dislike for the partner and its probably v clear and affecting things!

Well the dog sounds ok

The dog may speak but if it is in a forest does anyone listen

Your sister really jumped to an aggressive statement, frankly.

This sounds like a plot from the famous five.

please tell me your dogs called Timmy?