depends on the situation.
ANY situation involving nylons... 100% yes
all others (UB/Barefoot) about 75%-80% just fun... don't really engage in the second scenario too much.
For me it depends on the 'lee. With my hubby, it's always sexual; with male friends, it's usually flirtatious; and with female friends it can be either playful or flirtatious/suggestive depending on the particular friend. (Currently, I only play with the hubby and one very close female friend.)
Depends on the lee and/or ler. To me it's about 75% sexual, 25% non-sexual unless it's me playing with my kids, then it's 100% non-sexual, of course...
Well, I can't really say anything that everyone else hasn't, so I'll just say that, for me, it isn't most of the time, but can be some of the time. It just depends on the mood!
Most of the tickling I ever see outside of my house is almost always candid and (most likely) non-sexual. But I've never had a chance to experiment with a sexual tickling within a relationship yet 🙁
..so I guess it can be both! (basically a lot of what everyone else has already said)