Slang. It’s when thots use their vaginas in fucking random people so much it literally rots out. This is ideal for pimps because it makes them the most money.
Pimp: I expect you to make me 5 grand tonight.
Thot: what do you want me to do, besides tips and tricks? Pimp: you ever heard of thot twot rot? Thot: no. What is that? Pimp: it’s when thots like you use their vagina so much it literally rots out. Thot: Ohhh! Sounds great!