Things you don't expect to hear your boyfriend say at your girlfriend's house

In the kitchen helping decorate a cake for a 2 year old, I hear, plain as day, out of the mouth of my boyfriend:

Est-ce que ça te gêne si je me mets en slip?

"Do you mind if I am in my underwear?"

He doesn't even fight me anymore when I take the picture.  Just pulls up his thigh-highs.