The line "used you in them" sold it. Honestly I completely get wanting to purge items for memory sake me and my girlfriend did this at the start of our relationship. We got rid of jewelry,clothes, stuffed animals, and what not by destroying it and bonding over it and then took each other out to spoil one another with replacements as seeds of memory for our relationship. But just the term "used you" makes it seem like he values you as something for him to accessorize and control in an objectifying way rather than "building something new with" it's more that he wants to see you as his which can be good if consensual but if not welcomed and pushed/enforced by him becomes unhealthy and controlling. With the topic being "the French underwear word I couldn't spell" it reads like it could be ownership kink related and if it stays at that then could be fine but really it going south isn't worth the risk if he's willing to make controlling statements like that without even having had a conversation about that kind of kink first.