When My Military Buddy Got Too Friendly

So my husband and I are pretty open about stuff. He's deployed right now, which doesn't make things any less interesting for me. Anyway, this one buddy of his, let's call him Mike, has been around a lot lately. We've got this little thing going, just fun flirtation and playful teasing at first. But the other night when we were all hanging out together, it got really heated. He started making these eyes at me that made my heart race, and then he pulled me into a corner for what was supposed to be a 'secret mission' briefing but turned into something else entirely. We ended up getting pretty handsy, kissing, touching, and yeah, there's definitely some chemistry between us. It was all consensual though, no hard feelings with my husband about it. He knows the drill and is totally okay with me exploring these things while he's gone. So here's what I'm curious about: Have any of you been in an open relationship or played around with friends when your partner wasn't there? What were those experiences like for you?