AIBU for telling the girlfriend the truth?

[SquidwardTennisballs]

Hi everyone I need some real perspective here and I think this is the most realistic place to get it.
So bit of backstory I have been seeing a man for roughly 7-8 months now. Spent a lot of time together, had very intimate relations, he declared his love for me, wanted me to move in with him and wanted me to go on holiday with him. We hit a rocky patch just after Christmas and pretty much stopped speaking. We then got back to talking about mid January but haven’t seen each other since December.
We’ve been talking normal like we do, he went away for a week on holiday with a few of his “mates” around the end of January and we had arranged to see each other.

However I have just found out that he has a girlfriend that he’s had for quite a while. I had absolutely no inkling of this girlfriend, there was absolutely nothing on any of his social media about her. I only found out through some accidental stalking. I confronted him and all I got back was a sorry. Turned out the holiday that he was on with his mates was with her baring in mind that whole holiday he was sending me dick pics and other explicit stuff.

I decided to tell the girlfriend as I didn’t think it was fair for him to do that especially after all the conversations and things me and him have done together. He is now however going ballistic at me saying that I have ruined his weekend with his kids, he now had to take them out and I’ve ruined everything. She has not yet contacted me about this whole situation but I imagine she will at some point.
I just want a realistic opinion that I did do the right thing and yes maybe I’ve ruined a relationship which I feel horrendous about and it’s really knocked me but this girl has spent so much time with him and had plans with him I just thought she deserved to know. So AIBU or did I do the right thing?
Thanks everyone (if you want to berate me about the situation then go ahead as I couldn’t possibly feel worse about myself than I already do)

To be fair, the ex girlfriend is being fine with me even though I’ve completely ruined her relationship. I do feel so sorry for her as she had no idea about me just as much as I didn’t know about her.

Bless you. You’re not a flabby, stupid sidepiece. After this I suggest you think about working on your self esteem - might also help you meet a higher calibre partner next time.

I wish someone told me 🤷‍♀️.

You've done her a big favour and he had it coming. So - YWNU.

You have not ruined the relationship. He cheated. He lied. He ruined the relationship.

@ZenNudist the OP is involved ffs! She was in a relationship with this cheating bastard, thinking it was exclusive when he actually already had a girlfriend! Jesus 🙄

Thing is if you'd kept quiet, he's highly likely to have done it again and who knows maybe there would have been kids or a marriage by then, at least she's got out before that. He's angry at you because he thought he was invincible and could get away with acting like a total scumbag. I hope you're ok, all this must have been very difficult.

I would want to know before wasting my time or getting pregnant by a ceating loser

@SquidwardTennisballs

You haven’t “completely ruined her relationship”. Stop saying this. Stop repeating this. Stop internalizing this. It is not your fault. It is directly HIS fault for cheating. Repeat that to yourself. You are not guilty here at all. Absolve yourself.

So she was on the scene before you? Poor woman.

The dick pics would’ve made me dump him anyway. Why on earth are men so obsessed with their penis? And why do they think others must also revere and be fascinated by them? 🤮

To be honest, if they are living together, it's odd she didn't question why she wasn't mention at all on social media, unless he had multitude accounts.

Thank you everyone for your kind messages. It is a live and learn kind of thing but my god it doesn’t half hurt!
@Dontdisturbmenow as far as I’m aware she did question it but I don’t know what his response was.

This should be a natural consequence for any man who cheats. He should not get to come out of the other end of committing a betrayal and using another person untouched.

Or woman.