I get annoyed when that happens, but i've noticed that my ex's that i'm still friends with, find that it gives us something to talk about.
I found it really odd the other day when my manfriend was fucking around with my ipod in the car and put on pretty girls make graves.....I had NO clue he even like them. and I thought it was a little unmanly, but I went with it.... now THAT bugged me.