Married and looking.... maybe..... possibly.......... probably not

I've been together with my husband for seven years -- married for five.Last June we met up with a guy off Grindr to exchange blowies and I had to take a crap load of anxiety meds just to meet him - after the blowies he left and we deleted Grindr.The other night I found myself bored and told the hubs we could download it again and see what was out there.Well, I found a guy who works for the same company as me but in the building next to me. I was jokingly saying I was going to exchange blowies in the bathroom at work and the hubs said go for itI asked him why he's so okay with it and this was his response "That's why when things like that are set into motion you set ground rules! I love you and I'm married to you so clearly I'm not going anywhere regardless of what we're to possibly happen with anyone else"I'm fine with me doing it but I can't bare the thought of him doing it which is why I haven't.I'm scared he'll leave me or find someone better. Skinnier, or younger - anyone in an "open" relationship that can help guide me to where jealousy isn't a thing? Or is this something i should just let happen and react later?