It’s not you at all. It’s him.
How annoying. Low class. Rude.
Also people who brag about being good in bed, typically are very bad hahah plus he likely doesn’t have all these experiences he is bragging about. People who brag how wonderful they are, never are that wonderful at all or they wouldn’t have to advertise. Ignore him or if you feel like embarrassing him, ask what’s the reason for this oversharing
Gross