Woah. Wait a sec, here.
If you've got friends that aren't into the topic, and you keep bringing it up around 'em, against their wishes, are you truly surprised that they don't dig this?
Doesn't matter WHAT the topic is.
I agree wit' Maggie, that way. Many of my closest friends know I'm into this, but the topic doesn't come up wit' them, 'cause they're not into this. I don't dig hearin' about waterplay (peeing games) either, but there are folks who REALLY dig that. If a friend dug it, so long as I don't have to hear about such all the time, swell.
Keep in mind that, for some, tickling ain't a positive. Some folks don't dig the sensation. Some folks got tormented as youths. Some don't associate it wit' sexuality. There's a bunch of good reasons why someone wouldn't wanna go there.
If you bring up a topic wit' someone, and they don't wanna talk about it, ask yourself if it's something you NEED to talk about with them. If so, and they won't, you have a problem. If it's not necessary, though, don't go there. There's thousands here you can talk to. THOUSANDS. There's gatherings countrywide, and it's spreading. You can MEET folks to talk to about such. Folks from here even WANT to talk about such.
Gotta respect a friend's boundaries, after all. It's just an awkward situation, man.
My $0.02,
dvnc