We have friends - a couple - who tried dance classes - as "something they could do together". Didn't quite work out that way, as the guy seems to like dancing, and is good at it, and his wife is merely OK and not bothered.
So he gets to dance with other ladies - no doubt some married, some widowed, and some perfectly single. He's still married - and they still get on OK - but this was an unexpected outcome.
Trouble with that approach is that you might need to break into the scene with a lady - so maybe hire one for the evening. :)
[I refrained from saying for the night!]