Maestro raises a good point. I myself don't have a problem playing with friends... well, especially so now that I'm not attached - but if i were, that would be a totally different story. Because yes, the fetish/experience/whathave you is sexual in nature to the majority of us.
I'm not saying that tickle play necessarily has to or will lead to sex, not at all... just that most of us would be kidding ourselves if we said it wasn't arousing, even among friends. So for me to do that with "play partners" or what have you, in the context of while I'm in a relationship? Unless I had the coolest g/f or wife on the planet, that would more than likely be a no go 🙁 She would have to be cool with it for me to engage in any kind of play like that or I couldn't live with that on my concience every day.