Basically the submissive top version of the term"fucktoy"
Could also be written as "Spermtoy" or "Sperm-toy"
(Probably has breeding kink undertones, can be used for both gay and straight sex)
Boy1(getting his cock ridden): Ngghh~!
Boy2(riding Boy1's dick):*Twink-ass chuckle* Awww~ I'm gonna make you my sperm toy now...