Green’s Dictionary of Slang

bit of rough n.2

[i.e. a SE rough person]

a lover, orig. female but from mid-20C male, from a lower class and tougher background than their partner.

[UK]Spare Rib Dec. 36/2: In this play a bit of fluff comes home to her bit of rough after being raped by her ex-husband at an arty-party.
[UK]A. Hollinghurst Swimming-Pool Library (1998) 196: A bit of rough, you might say.
[UK]T. Blacker Fixx 189: Then she could go mad [...] fall for her bit of rough.
[UK]M. Amis London Fields 112: Keith knew that some of these rich ladies liked a bit of rough.
[UK]Indep. Rev. 16 July 7: The traditional posh girl falling for a bit of rough.
[UK]K. Sampson Powder 20: They’re howling for a bit of rough, this lot!
[UK]J.J. Connolly Layer Cake 56: They make a strange couple, the lady and the bitta rough.
[UK]Guardian G2 28 Dec. 14: She runs away to shack up with her new bit of rough in the dodgy area where he lives.