Wiktionary
have it off
vb. (context idiomatic English) to engage in sexual intercourse
WordNet
have it off
v. have sexual intercourse with; "This student sleeps with everyone in her dorm"; "Adam knew Eve"; "Were you ever intimate with this man?" [syn: roll in the hay, love, make out, make love, sleep with, get laid, have sex, know, do it, be intimate, have intercourse, have it away, screw, fuck, jazz, eff, hump, lie with, bed, have a go at it, bang, get it on, bonk]
Usage examples of "have it off".
I'd have it off the hinges if that was the only thing that would work, but after a moment it opened.
I shall never want to have it off you, if you say such nice things to me!
Master Gill tugged at the neck of his disc-covered jerkin as though he wished he could have it off.