Green’s Dictionary of Slang

mutton-monger n.¹

a promiscuous man.

1532		T. More Confutation of Tyndale Answer VIII Pt I 59: Motenmongers, pryapystes, idolatres, horemaysters, and sodomytes.
1542		Udall (trans.) Erasmus’ Apophthegms (1564) Bk I 62: Now a mischief on the hartes of these naughtie & wretched muttonmongers, that haue brought soche a singulare good thing as this, in slaunder & infamie.
1589		Rider Dict. n.p.: A Muttonmonger [...] Mulierarius.
1598		Florio A Worlde of wordes n.p.: Feminiére, a whore-monger, a frequenter of women, a mutton monger.
1600		Munday & Drayton Sir John Oldcastle II i: har.: You whorson bawdy priest. sir john: You old mutton-monger.
1607		Dekker & Webster Northward Hoe IV i: Fetherstone, like a crafty mutton-monger, persuades Greenshield.
1611		Chapman May-Day II i: Any other man, she says, might better adventure with the least thing changed about ’em than you with all, as if you were the only noted mutton-monger in all the city.
1629		J. Taylor ‘Great Eater of Kent’ in Works (1869) I 143: For though he be chaste of his body, yet his minde is onely upon flesh, he is the only tugmutton, or mutton-monger, between Dover and Dunbarr.
1639		J. Taylor Crabtree Lectures 184: Sirrah, I hear you are a Mutton monger and run after laced Mutton.
1642		G. Calfine A fresh bit of mutton 6: [S]ince I perceive you are such a great Mutton monger, pray what part of the Mutton shall I assigne [...] I commend unto you the rumpe, and least you should blend legs with your sisters.
1680		M. Stevenson Wits Paraphras’d 105: Here came a Stroler starv’d with hunger, / I ask’d him for my Mutton-munger; / Lives he?
c.1698		B.E. Dict. Canting Crew n.p.: Mutton-monger a Lover of Women.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1772		Bridges Burlesque Homer (3rd edn) 99: It joys me now that they no longer / Need fight, but that d---d mutton-monger.
c.1786		Grose Classical Dict. of the Vulgar Tongue ms. additions n.p.: Mutton Monger, a Man adicted [sic] to Wenching.
1796		Grose Classical Dict. of the Vulgar Tongue (3rd edn).
1811		Lex. Balatronicum.
1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc.
1847–81		Halliwell Dict. Archaic and Provincial Words II 568/1: MUTTON. A prostitute. Mutton-monger, a man addicted to muttons.
1896		Farmer Vocabula Amatoria (1966) 74: Coniste, m. A wencher; ‘a mutton-monger’.

In phrases

go mutton-mongering (v.)

to have sexual intercourse.

1896

Farmer Vocabula Amatoria (1966) 235: Ribauder, To copulate; ‘to go mutton-mongering’.