Am i wrong?

Would this bother you? I'm willing to come to the conclusion that this may be a "me" issue but am I wrong here?

We are visiting my MIL for the weekend and my husband was showering and he came out of the bathroom and walked naked through the living room to get some clothes from the dryer knowing me and my MIL were in there.

He's done this before and I've told him I think its weird for a married man in his 30s to walk around naked in front of his mom. He shrugs and says things like "its not like she hasn't seen me naked before. It's no big deal."

And what bothers me even more is when his mom will buy him some pants for xmas or something and she'll ask him to try it on and he will walk into the bathroom and she'll say "why so shy all of a sudden?"

Another time she walked in to the room we were sitting in holding a tablet and asked "Where's the tape measure? I need to measure this to see what size cover to order" my husband playfully grabbed the tablet from her hand and held it to to his crotch and said "8 inches!" Then laughed. She replied by saying "How can you measure something that might be 8 inches with a 5 inch thing"? She didn't laugh.

I felt like I was going to vomit.