"Not as small as it was"

My boyfriend just told me I have a big vagina pretty much!!!! We were trying to have sex but his sister came in the room and I think that he just wasn't as hard after, and that's when we tried to do it. He also worked at 4am and I understand that he's tired but what the fuck I got so angry at him saying this. I'm 23 weeks with his baby! He said it wasn't as small as it was and I'm over here thinking its tiny cause it's hard for him to put it in every time 😭 I'm so angry and like uggghhh idk what to do.