Bug chasing became a thing in the gay community during the ridiculous bathhouse years in San Francisco. STDs were extremely prevalent, but largely curable before AIDS, and fucking around invariably meant getting them. Contracting an STD meant you were having a lot of sex, which meant you were behaving like a proper gay man. So, STDs were a low-risk way of virtue-signaling your gayness. Or some stupid shit like that. When AIDS showed up, it killed a lot of men because of this attitude. I guess it’s now become “low risk” enough that it can be some kind of kink. Fucking weird, but that’s all gay sex fetishes.