Sexual attraction among couples

We are friends with another couple, and we often hang out together with our group of friends. We are all in our 50s. I've noticed there’s definitely some sexual tension between me and his wife, and it seems like he’s shown interest in my wife as well. I’m unsure how my wife feels about him, but she’s very close friends with his wife. It seems like he might be interested in exploring a more intimate relationship between all of us. How should I handle this situation?