I need advice or opinions

Kayla • Had a miscarriage in April of 2020 at 12 weeks 😔 Me and my fiancé decided to try again this year ❤️ TTC baby #1 🌈👶🏻 (pregnancy #2 👼🏻)

So here’s a nice lil story, in November 2020 my boyfriends cousin was leaving for the army so they had a get together before he left .. I get off of work to meet my boyfriend there ( he was already there for about 2 hours) I get there and I have a strange gut feeling that one of the other girls there he maybe had a thing with them, so we leave the party a few hours later and I ask “ which one did you have a thing with?” He called me crazy bc I some how knew 🤣🤣 and says they never had a thing his cousin was about to umm “ do the you know” with his girl so he asked her is she wanted to and she told him no and he says he don’t find her attractive never did he just wanted some 🍑That’s all . Any ways fast forward to today they are having a party for their 2 year old daughter’s birthday. And she’s going to be there. I’m one of those girls who get stuck on the past ( I know that’s not good ) I basically talked to my boyfriend now fiancé about it and I told him I trust him around her I’m just uncomfortable about the situation. His response was “ we will be walking in together both wearing our ENGAGEMENT rings and we will be leaving together I love you idgaf about her just leave it alone nothing happened. Am I wrong for feeling uncomfortable ??