Not married here (engaged), but my girl and I are wanting to do stuff like this in the near future. We're part of a local FetLife T.N.G. group (The Next Generation, a group for kinksters on the younger side of the spectrum) that hosts a vast spectrum of events, from movie-nights to specific play nights. There aren't anything specifically for tickling so far, but we're looking forward to engaging with others with bondage sessions and some other interesting play.
Though we are in a monogamous relationship, we'd find it fun to include others in our play, yet still preserve the integrity of our relationship. It's all about the communication. 🙂 It's a fantasy of ours to be tied (and tickled) together, or helping other kinksters do kinky things to each other. 😛