Not forced but I’ve shared my dirty undies kink with many partners and I’ve swapped my dirty ck’s for their dirty panties many times. Many times it was their idea. I’ve come home to my partners wearing my dirty chones they pulled out of the laundry bin or ones I left in bed with them from the night before. I’ve also had my ex put her filthy panties in my lunch box for me to find later.
Also had a ski buddy forget to pack her panties for a week long trip so I loaned her my ck’s. She loved them and I ended up sharing my dirty secret and she loved it.
Hope these experiences give some naughty ideas to others who read this. My experiences weren’t with messy undies necessarily… but lots of wet, creamy days old worn panty sharing. The closest to messy would have been with my ex but only heavily ass stained and skid marks.
I did see a Mistress who to punish me for wetting and shitting my panties in front of her, put me in a nappy, but only after she did a huge poop in it. It felt incredible having Mistress’s mess caked over my sissy nappies bottom.
A few times been with another guy and we’ve peed into each other’s pants. Haven’t worn another guy’s wet or poopy pants yet, but it is one of my fantasies I hope to make come true with a friend I met on diaper-bois.