Does Leicester have a red light area? If so, there's bound to be some auld slapper who'll happily toss you off behind the bottle-bank for a tenner.
Or buy a gentleman's relaxation magazine specialising in the over 40's. You'd have to give that a bit of help, of course, but you'd get change out of a fiver, and it will have a 'cum as often as you want' policy.
Hope that helps