I'm fucking obsessed. It is a true fetish for me. If I have a pair of her panties to wrap over my cock and jerk off with I'm a pretty happy camper.
Sniff them after she cums in them, look at them on or off of her, molest her through them, push them aside or push them into her, paw through her drawer full of them, sneak some, demand a pair, take a pair right off her and pocket them, request a certain pair or style be worn, rip them strategically or right the fuck off, go panty shopping with her and select her purchases, cum on them while she wears them, cum on them in secret and leave them on her pillow or back in the drawer for her to find later, push them in her mouth for a gag, pull them over her head for a blindfold... Scold and punish her for not wearing them (dirty whore, no panties?) or not wearing the right style/color/ugly ones.
BTW: thongs and g-strings need not apply. That earns derision and abuse. I need some fucking material to work with or I am not a happy camper.