How to approach a friend?

Hi,
I've a dilemma. I'm an elderly married male that's had bisexual feelings for many years and would love to find another man for a bit of fun. It's not easy.
My wife and I take our dog to the local dog park each day and there is a guy that's joined our 'group' that (I think) is putting out feelers. Obviously I can't be sure so have to be very careful. It's obvious he likes me and we talk about many things but occasionally he mentions porn in a humorous way from time to time and we laugh it off but I wonder if he might be feeling me out. How can I raise the subject with him without putting our relationship within the group and my wife at risk? I'm afraid to say anything in case I've got it completely wrong.
Thank you

To tell the truth it's not easy to "read" some one. There was a guy in transitional housing who proclaimed frequently he was "straight". I had an opportunity to take him long distance for a job interview. As the miles spooled off,we talked and were frank knowing that if word filtered back there would be no question who spilled the beans. He admitted to "leaning that way". I was straight up and told the unvarnished truth. Kind of hard to jump out of a car going 70 on the interstate. At my age (71) there's not much that can surprise me any more. We agreed to be discrete and that was that. We talked more on the way back feeling a lot more relaxed. I helped him move into his own place about a month later. I would have liked to have enjoyed going farther but respected his wishes. I do know he had some nice "equipment " stashed in his jeans. My best advice is play it by ear. Perhaps you can go to the dog park alone and see if he drops any more "hints". Be a friend first. Sometimes us single guys would just like someone to hang out with without having anything hanging out.

Nest time he makes a porn joke............a simple I wish, but the wife would go nutty.

If he offers to watch together, take him up on it. When you meet, ask him what kind he likes, no matter what he says, ask him what he think of the newer trans porn

Agree with him about porn and ask if he wants to watch some with you at his place. Make up some story about jacking off with other guys in your youth to a porn stash a friends parents had. Nothing "gay" so far to put a relationship at risk. If he is amenable, then see where it goes. If it looks good, then offer to help him or ask him to help you.