A euphemism for having sex that originated on the Facebook fan page: RIP Severus Snape; The Bravest Man I've Ever Known after an admin said he was slaying dragons with his admin girlfriend.
A phrase that someone will use referring to them F*#king dicks, sucking dicks, jerking dicks or just plain making a dick Cum. Usually used in a gay manner, it can also be used by women.
Jimbo: Slay any dragons this weekend bud?
Bud: Yeah, me and Claire got frisky in the back of my Labaron. Then we had sex. So yeah I was slaying dragons this weekend.