Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: Recently one of my friend's girlfriends came to town and a few of us went out to hang out and get drinks, note that this friend does not live in my town, so he was not present at this hangout. I will call this friend the 'boyfriend' and his girlfriend just the 'girlfriend'.

During this hangout, we spent some time sharing stories about the boyfriend, most of which were fun but also listening to her complain a bit about different fights and such. At one point in the conversation, the girlfriend asks us if we know about the one time the boyfriend had sex previous to their relationship (at this point she had enough to drink to be pretty unfiltered). The boyfriend had told a couple of us the story before, and it occurring when he had traveled to NYC.

Initially I had assumed the girlfriend was just trying to get us to bait information out of us, but when she referenced NYC I thought perhaps the boyfriend had told her about it before. When I replied that I knew exactly what she was talking about, she didn't believe me and I replied that it was with 'Alice'. Apparently the boyfriend had told the girlfriend a different story about who he had slept with in NYC, due to his history with Alice.

This resulted in her confronting him, them getting in a big fight, and him angrily messaging me calling me a liar and ultimately blocking me. The girlfriend messaged me as well, apologizing, and explained this was a big issue due to him lying about big things like this in the past.

Am I the asshole here? I feel very guilty as it feels like I am causing them to potentially break up. I am fully aware that perhaps we shouldn't have been talking about that subject at all, but the atmosphere at the time seemed like telling funny stories rather than gossiping, and at the time I genuinely thought we were both referencing the same story.

TL;DR: Accidentally exposed friend's conflicting story to his girlfriend resulting in a fight between them, AITA?

accidentally getting my friend in trouble with his girlfriend