<human>: I'll call him Jason. Jason and I have known each other about eight months now. We talk pretty often but live about an hour from each other and we have conflicting work schedules so we don't have sex often. He really likes my butt so I'll sometimes send him a picture of it, usually in a thong. 

About two months after Jason and I first met, he told me he likes to collect thongs of women he sleeps with. I told him that's weird but we never really talked about it. When we've had sex since then though, he tells me he wants one of my thongs. I've always said no because again, I find it not only weird but also just creepy. 

Finally, the other day, he was super busy. I had a glass of wine and said "if you give me advice on this work situation, I'll mail you a freaking thong." He called me, gave me advice. Now he keeps asking for the thong. 

Now? Jason won't stop mentioning the stupid thing. We had plans to hang out tomorrow and I told him that I don't really feel comfortable giving him a pair of my undergarments. He went off on me saying I made a promise and if I don't do it he will never trust me again and I'll be dead to him. He said if I'm not comfortable giving him a thong then he's not comfortable hanging out with me. 

Am I wrong to be uncomfortable with this? What would you do?

Can you give me a shortened version of the text?
<bot>: my FWB likes to collect thongs. I made an off handed comment that I'd mail him one. I'm incredibly uncomfortable with this and he's upset. Who's in the right?