"Waifu sex simulator" is a term used in adult content, primarily within the anime or Japanese animation fandom. The concept of a 'waifu' refers to an idealized female partner, often from an animated series, who one might fantasize about or have strong feelings for. In this context, a "sex simulator" would refer to a virtual or simulated sexual experience with one's waifu.
In summary, the term 'waifu sex simulator' represents a fantasy-based adult content that involves engaging in virtual sexual activities with an idealized female character from a particular anime or animated series. This genre typically appeals to fans of Japanese animation and those who enjoy incorporating their favorite characters into their personal fantasies.