Green’s Dictionary of Slang

(US) to have intercourse with; thus boinky-boink, boinking n., sexual intercourse; boinkfest n., sexual intercourse.

1987		Eble Campus Sl. Spring 1: boink – have sex. x: ‘Look at that chick!’ y: ‘I sure would like to boink her.’.
1990		S. Morgan Homeboy 84: You know, it. Boinking.
1995		A. Heckerling Clueless [film script] What that man needs is a good healthy boinkfest. Unfortunately, there was a major babe drought in our school.
1999		Guardian Guide 20–26 Nov. 4: Say, did you ever boink Madonna?
2001		T. Kornheiser ‘The Best Pictures I Didn’t See’ Wash. Post 25 Mar. F01: And the emperor wants to boink his sister. But hey, it’s only a movie so it’s not really. his sister.
2006		Fleshbot 28 Oct. 🌐 Just remember: if you’re going to boink a jack-o’-lantern, make sure you blow out the candle first.
2010		K. Richards Life 52: He was exiled or degraded for boinky boink with little boys.
2012		L. Berney Whiplash River [ebook] [A] high-level congressional staffer [...] who she’d probably have to boink after this.
2017		‘Chelsea G. Summers’ on Twitter 20 Apr. 🌐 ‘Boink me, daddy,’ I whispered. ‘Boink me harder’.