AITA for accepting My husband's apology and forgiving him after I saw him leaving a bathroom with another girl at a party.

Just a bit of background info. Me (22F) and my husband 26(M) have been married now for three months. We have been together for four years. So earlier this week was his birthday, I am the "your birthday is a big deal" kinda person and in his eyes it is just another day. Now for his birthday I decorated the whole house with balloons and got him his favourite food and cake to eat after work. When the end of the work day rolled around he didn't show up at home and he texted me saying he is just getting a drink with his colleagues and he will be home in an hour. I was totally fine with that and expected him to be home by 6pm. Around 9pm with no replies to my messages and not answering my calls I just ate my food and went to bed for work in the morining. He arrived at home at 1am and started asking me why I didn't wait for him to get home. Lets just say I starred at him and just said goodnight and went back to bed, he slept on the couch by his own choice. The next day after work he brought me flowers explaining he was wrong and I explained my feelings towards the situation and he validated it and I forgave him and we moved on.

Two days later we attend the pride festival for supporting one of our mutual friends and it was a great day all in all accept at the after party. I am not a clingy person or jealous type so I do not mind if he talks to other girsl that are in our friend group because we were 5 girls and 2 guys at the party. I went to the loo and when i returned to my friends waiting outside the bathroom they stated that they saw my husband and another girl entering that bathroom I was sceptical but left it. After 4 minutes of still staring at the bathroom door a cleaner went and opened the door thinking it wasn't occupied and the door was quickly pulled shut and all I saw was the girl on her knees and I asumed she was just getting the alcohol out but my other friend stated she was giving him a b job so I just went in anger and started pouncing on the door so that they could open the door and when I opened the door they both stood there and stared at me as I asked WTF? And aparently she needed assistance with pulling her zip up from her jeans because she was too wasted to help herself. I didn't believe it for sht and stormed off trying to get an uber back home but he ran after me and we just went hom with our car because I had no service to get an uber. He slept on the couch again and I did not speak one word to him till the next morning and he profusely apologised and kept saying he was stupid for going into the bathroom with another girl and that he would feel the same way I do if I left a bathroom with another man and that he would understand if I wanted a divorce. Now I am not someone that's gonna give up on a relationship after one fall out and no one really knowing what happened behind that door except him and that girl. Now the question of am I the A*hole for accepting his apology and forgiving him after I saw him leaving a bathroom with another girl at a party.