Should I stay with him!!

So my bf went to uni and as a freshman he started flirting with a girl he was in a friend group with. She would flirt with him pretty heavily and try and sit on his lap and take pics of herself putting her head on his shoulder. There was an incident where they were all intoxicated and he was throwing up so they put him to sleep in her bed- she ended up sleeping in bed with him and she said that they cuddled. He said that he was so drunk that he has no memory after he threw up. Her friends told me that they have never sean him so drunk. I don’t know what to do or what to believe. He said the next morning she told him that they cuddled and asked about me, and he apologized for sleeping there and said that we were together. We broke up for about three months after this but ended up getting back together, I just am overthinking and am worried he is not a loyal man. He has never done anything like this before and is an amazing bf, so I am just puzzled in what to do. They would text occasionally as they were friends but he would also leave her on open on snap and would text his friends asking why she would act the way she did. I just need some advice-please be nice and let me know if him not remembering is even a thing or possible he says she must have had to come onto him idk tho

So my bf went to uni and as a freshman he started flirting with a girl he was in a friend group with. She would flirt with him pretty heavily and try and sit on his lap and take pics of herself putting her head on his shoulder. There was an incident where they were all intoxicated and he was throwing up so they put him to sleep in her bed- she ended up sleeping in bed with him and she said that they cuddled. He said that he was so drunk that he has no memory after he threw up. Her friends told me that they have never sean him so drunk. I don’t know what to do or what to believe. He said the next morning she told him that they cuddled and asked about me, and he apologized for sleeping there and said that we were together. We broke up for about three months after this but ended up getting back together, I just am overthinking and am worried he is not a loyal man. He has never done anything like this before and is an amazing bf, so I am just puzzled in what to do. They would text occasionally as they were friends but he would also leave her on open on snap and would text his friends asking why she would act the way she did. I just need some advice-please be nice and let me know if him not remembering is even a thing or possible he says she must have had to come onto him idk tho

Is he actively flirting with her, or is she just flirting with him and effectively taking advantage of times when he's inebriated?
One way or another he should stop getting blackout drunk. If you stay with him while he's continuing to get blackout drunk, you're going to have to accept that while he's that drunk anything could happen. That's a perfectly good reason to leave him.

Hi 🙂
Well I mean, you said yourself, he's not given you any reason to not trust him before, so maybe he is telling the truth? You say he's an amazing boyfriend and stuff, and you trusted him up until that incident, so I think it's possible that he's being genuine with you. If he's such a good boyfriend, he would never do you like that.
Either way, this girl you're talking about seems to be the catalyst in all of this, and a real troublemaker. I mean, it's girl code to stay away from guys with girlfriends, but even if you stuff girl code, it's just having a good moral compass really. It appears that she lacks that, in this instance.
If he was really drunk, it is more than likely that he doesn't remember anything. I don't think he's lying about this, as it is totally possible.
If you feel uncomfortable or anxious about him talking to this girl still, maybe ask him to stop talking to her or at least make it clear to her that they're just friends? He should understand and want you to be happy and comfortable.
Hope this helps 🙂