Text cheating at start of relationship

My sister's husband came onto me one night and I never told her about it. He was really drunk, he apologised afterwards.
I think if they'd only been going out for 5 weeks I would have told her, to warn her away from him. But as they were married and have kids I didn't want to throw a grenade into their lives.
I also feel like I'd get the blame, even though I didn't do anything.

OP I think you should leave him/her. They'll do it again the next time theyre having a hard time.

I let something like this go early in my relationship with my dh. I found flirty messages with his 'work wife'. He swore it was nothing, I kicked him out but a couple of weeks later took him back after much begging. Something was broken, to be honest but I tried to ignore it and bury it.

Found out a year ago he'd had a year long affair, probably not the first one. I'm two kids and a mortgage in now, and I wouldn't change my babies for the world but I would leave him if I had my time again. You deserve a real, proper love.

He's shown you who he is with his actions. My advice is to believe him. You will look back and be glad that you walked away.

Re. your sister; people are also rarely black and white, super simple.

Her behaviour could have had a whole mix of motivations behind it;

Not wanting to hurt you by telling you.
Not wanting to be the bad guy who broke up your new relationship.
Not wanting to be accused of jealousy.
Thinking he was being foolish/inappropriate but maybe it wasn't bad enough to tell/drop him in it.
Maybe some unpleasant competitive satisfaction/superiority that your bf was interested in her to some extent.
Thinking that you might still stay with him and then things would be awkward as fuck
Etc. etc.

It's probably not just one simple reason/motivation.

I think what would always bother me is, if my sibling had been receptive to their texts, what would've happened? Would he have dumped you and moved on to them?

Bin.

Btw no one is perfect and neither is he.

Yuk. Bye bye.

It's amazing how many people have stressful situations that can only be relieved by sexting someone or in my case, abusing them. (Me being the victim).

Whether your sibling is jealous & competitive or not, he's still a problem.

A decent guy who fancies his girlfriend's sister or thought she fancies him (or senses some unhealthy sibling jealousy/rivalry) would stay well clear, not be messaging the sibling flirtatiously and with sexual innuendoes.

"I genuinely felt I'd found the person I'd be with forever. "

And now you know your feelings can fool you. Their perfection was an illusion, just something you projected onto them. You didn't really know this person, you saw what you wanted to see.

Dump the scum bucket, then take time for yourself. You're going to have to take a deep look at some of your relationships like with your sibling and figure out what will work for your long term goals and interests.

I feel a part of it with my sibling is jealousy, they showed their dislike to me being in a relationship from the start, yet did this and I can only think it was from a jealousy point and they liked the attention.

It's possible there's an element of jealousy or competitiveness and that she kept schtum partly because she liked the feeling of knowing that your bf fancied her and flirted with her/came onto her ..and that'd she'd always know that (and you wouldn't).
That she could tell herself that he may be with you, but unbeknownst to you, he'd have cheated with her or left you for her if she'd reciprocated (I'm not saying he would have, just that people tend to be egotistical) .....and she wouldn't have that smugness and superiority about your relationship if she had told you and you (likely) dumped him.

It's possible.

But the fact remains that it appears he started the flirtation and sexual innuendo, and that she did not reciprocate or escalate it.

And even if she was flirtatious etc. in person - a decent guy would just be like "right, her sister fancies me/is flirty ...not going there!". They would just avoid the situation. Not seek it out by messaging her, being flirty etc.

The first year of my last relationship was amazing and I truly thought I’d be with him forever. I’d never felt love like it.
Then when the honeymoon period ended the wheels started falling off and I realised that it wasn’t as perfect when we got down to real life and all that entails. He didn’t cheat but it felt like it when his words and actions never aligned.
You’ve found this out only 6 months in, and you’ll get over the hurt. Not immediately but you will. You didn’t see him as he actually is, you couldn’t in just 6 months. It’s painful but you really have to move on from him.

How can a person be so perfect but has done this.

At 6 months in, you are very much in the middle of the honeymoon period.

The fact is, you only thought they were perfect because you didn't know they were coming on to (or at least flirting with) your sibling early on.

And as I said, your sibling - while they should definitely have told you - apparently did not reciprocate .... So his behaviour could have been much worse if that hasn't been the case.

At 6 months, you are still getting to know him.

You now know this.

The sooner you get rid, the sooner you can get on with finding a partner who hasn't crossed a line like this. Just saying.

It appears your sibling did not return the flirtation/sexual innuendo and implied he (?) was being foolish, inappropriate etc but that they would do him a favour and not tell you.

(That definitely wasn't a favour to you, but anyway ..).

What I'd want you to think about is what would have happened if your sibling had returned the flirtation/sexual innuendo.

Was he going to cheat on you with your sibling?
Or dump you for your sibling?
Or just keep flirting and being sexual to your sibling?
Or do that for a while but kindly stop at some point?

None of them are possible scenarios that you would ever have been facing with a decent person.

I don't think he/she did it because they were going through a hard time. I think he/she fancied your sister when they met and decided to flirt with them/come onto them and see what happened.
Because they're that sort of person.

They're not magically a different person six months later.

Even if they didn't have feelings for you at that time - perfectly understandable at 5 weeks in - a decent person still would not be behaving like that.

They would just think "her sister's hot but I'm seeing her/I met her first. You don't go there."

(If they thought they'd met the love of their life (in your sister) through you, a decent person would end the relationship with you and give it a loonnng ass time and then approach your sister. Even then they would understand that having dated one sibling, it might never be ok with everyone to date another).

I’d run as fast as you can. If you hadn’t yet agreed to being exclusive and he was keeping his options open that’s one thing, but to be messaging other people when you’d committed to each other AND that person being your sibling is a boundary crossing that defies belief. I can’t even think why on Earth you would entertain staying with him when he betrayed your trust so clearly and so early, and when you would never be able to rest easy about the relationship with him and your sibling again.

Trying to hook up with your sibling?

Fuck no.

Now you know your "friend" (this is not a partner) and your sibling are both untrustworthy and have zero care about your feelings. Your "friend" is too shitty to make partner unless you're a doormat.

Anyone whose stress response is to cheat with the most inappropriate person they can find is not a keeper if you want a happy life. This is the early days when they should be on their best behaviour, not at their scummiest.

The thought of the sibling and the partner exchanging sly glances etc at family events, ugh!!! I bet they said “it’ll be our secret/just between us”. The pair of them would make you sick!

This

Hard no. Ditch him.

How did you find out? I'm guessing he didn't confess?

Your partner knew who you were talking about because it was your sibling and therefore the only one you would likely to find out about texts. They won't be the only one they've been flirting with.

That's true.

It's not really the irrefutable evidence your mate thinks it is that they've only acted this way to your sibling.

This is really gross. How are you going to attend family events together with this on your mind?

I'd be amazed if your sibling was the only one they'd messaged like this. And if they are the only one....then he must really, really fancy them to break his normal behaviour of not doing this.

Your sibling isn't any better than your (hopefully ex) partner.

The appropriate response of a sibling to receiving flirty texts from their sibling's new relationship is Yuck! And shooting them down in a barrage of hellfire for even thinking it was appropriate. Then telling said sibling.

Your partner knew who you were talking about because it was your sibling and therefore the only one you would likely to find out about texts. They won't be the only one they've been flirting with.

The relationship is not strong, couple of times a week for 6 months is barely anything. You can do better. Raise your bar. This one is a tripping hazard.

Your sibling continued this text exchange and never told you? Completely out of order.
What happens the next time he’s going through a stressful situation, will he do the same and just choose someone you don’t know? He’s learned that you’ll accept being deceived if you stay. And probably just get cleverer next time.
How could you spend your life at family events seeing them together and knowing that neither of them respects you?
Bin him now or this will only be the start of many similar posts for your relationship.
You can’t get trust back when it’s broken less than 6 months in. You’ll always have doubts. Find someone who won’t treat you like this.

Ps your sibling is a tramp, sorry. I wouldn’t be bothering with either of them going forward. Just be warned they might get together as they don’t seem to have any sense of decency.

"I have very strong feelings for them*

You have very strong feelings for the person you thought they were.

What would you have done if - 5 weeks in - you'd discovered this about them?

They, and your sibling, have deprived you of that choice. They've made this much more painful for you.

But you will recover from this.

I would have said if the rest of your relationship has been great since, some texts when you were getting to know each other aren’t a big deal. But your sibling???? Absolutely not. Bloody weird never mind how disrespectful and frankly embarrassing. Get rid.