Places in London to meet "grown ups"

[sjuk]

We're in the UK and wife (classy, attractive, early 40s, looks 30s) prefers meeting guys in a more "natural" way - meeting eyes in a bar or club and then flirting and getting together. Any recommendations on good bars, clubs, areas in London. Not looking for the obvious nighclubs which tend to be very young (youngs and 20s) but somewhere classy black guys in their 30s and 40s hang out - but still "available" so to speak. Hotel bars have been disappointing, as have high-end nightclubs.