Is it normal that i like to wear men underwear that are dirty

I love to ask guys if I can have a pair of underwear that they have worn for a couple of days for my collection. I love to put them on and to smell them. It don't matter if they are straight or gay. My collection is getting large as it is every time I see a a friend I will ask for a pair. Most of them are like sure no problem would love to give them to you. Most are straight men