As noted OP missed the green light to play, maybe it was a spur of the moment thing for the guy or maybe he's looking for more. Start a conversation with him, just complement his physique, shoes, or water bottle it doesn't really matter. You just need to break the ice, and see if you get a vibe from him. 'Hey, saw you in sauna the other day, you've got a great physique." "I'm sure I'll see you in there later."