Sitting like a hooker?!

So when I'm at home with just me and my bf I will sometimes sit with both of my feet up on the couch with my legs spread. It's comfortable sometimes lol. I think of it more of how a guy sits but my boyfriend tells me don't sit like that!!! You're sitting like a hooker! I don't want a hooker!! He says that and gets mad everytime I sit like that but ??? We're here alone why does he care??