Relationship question

Umm why does my boyfriend bring up shit he gotta do when his family around? It’s not everything but it’s the shit that he thinks will start a fight…like today his grandma was visiting the baby and he says “hey babe I gotta get outside and help this dude with building shit in my garage”

Idk how that would start a fight but basically I been staying home with our 6 week old all day I spend with him all day, all night basically he’s my entire life. My boyfriend gets to leave the house and work and do other shit throughout the day. I do get to go out here and there but basically I am home bound. I’m on here asking if someone can answer my question because if I ask him it might start a fight. Anyone able to help me figure it out?