Green’s Dictionary of Slang

1. to have sexual intercourse; usu. as peg up/down.

1850		Man of Pleasure’s Illus. Pocket-book n.p.: The abbess, who is a slashing piece, is good at cribbage, though she will let you peg her.
1861		N.E. Police Gaz. (Boston, MA) 12 Oct. 5/3: The ‘Jew‘ played a great cribbage game [...] We wonder if he found his ‘go hole.’ [...] His friend could not ‘peg’ faster than he could.
1937–84		Partridge DSUE (1984) 866/1: from ca. 1850.
1993		B. Moore Lex. of Cadet Lang. 262: peg to fuck. Not a common term, but cf. possum pegger.

2. for a woman to penetrate a man's anus while using an atrificial penis or ‘strap-on’.

2004		Urban Dict. 23 Dec. 🌐 pegging anal sex reveresed. instead of the man sticking his penis up the womans butt, the woman wears a strap-on and sticks it up the mans butt.
2016		Urban Dict. 19 Mar. 🌐 pegging Often used to spice up a couple’s sex life, pegging is when a woman wears a strap-on dildo (or holds a handheld dildo/vibrator) and uses it to have anal sex with her male significant other.
2020		(ref. to 1998) Wikipedia 🌐 Bend Over Boyfriend (BOB) is a series of sex education videos [‘released in 1998’] covering the practice of a woman penetrating a man's anus with a strap-on dildo [...] The videos star sexologist Carol Queen, who discusses pegging and also demonstrates the practice with her lover.
2020		Twitter 16 Dec. 🌐 Sorry luv, utter rot. Even my 76-year old mum knows that's what pegging is.