Sexy fun times
37 yr old man, with a longterm female partner who MAY want to join in for sexy fun times!! :P If not, well, discretion would be the go until the situation required otherwise.
Flirty, loose and adventurous. Ideally, we'd develop a friendship (ie, NOT a relationship) based around shared interests, but the meeting place would begin with our shared interest in SEX and lots of it.