Hooking up means sexual activity. Kissing (or making-out) is not hooking up. Any type of oral, vaginal or anal sex is considered hooking up. Hooking up means anything BUT sex. Some people use to for just making out, but usually its used for oral sex.

What does hookup mean in slang?

Hooking up is used to describe a sexual encounter (vaginal, anal, or oral sex) between two people who are not in a dating or serious relationship and do not expect anything further, their study says. Theres more risk than having sex when its planned.