There are probably many reasons ;-)
Several of the previous posters have hit on a few triggers for me...
I too have only attraction to adult female feet, and certain shapes do nothing for me (In particular, the larger, masculine, or extremely athletic types). Also, for me, it goes beyond just tickling... Kissing her toes while giving her a gentle massage is always a turn-on. Mine goes into a bit more complexity than the "common" foot fetish. I'm heavily into nylons, pantyhose, bodystockings, knee-highs, etc on her feet. the sheerer ,the better (thick opaque tights and socks have no effect). The nylon is such a big part, that my wife is the only person who I have ever tickled barefoot! She is one of those women who are more ticklish in a sheer pair of pantyhose. So ticklish in fact, that she usually only indulges my tickling requests during our "most intimate relations"
😉
Anyway (I tend to ramble, lol),
I'll try to forget the nylon part and just focus on the feet...
1. The curves!
especially the arches. Pleasing to look at, fun to tickle, and for the other hardcore foot fans, a properly executed footjob is more satisfying than if she used her hands (mostly because the feet already turn you on)
2. The feel!
the bottoms of her feet are usually a mix of textures, the roughness of the heels, the tautness of flexed arches. Yet the tops of her feet are always soft and silky smooth, especially right above her toes.
3. Those Toes!
The one thing that was fun about the barefoot tickle sessions was that now the spaces between her toes were easily accessible. they were usually protected by the nylons. It's fun to watch them wriggling when you are tickling her, yet it's erotic to feel them wriggling in your mouth.
4.No Shortage of sightings!
You can see feet proudly displayed in strappy sandals, barefoot, mules, etc... at ANY time ,only the face and hands go uncovered more. It's strange, how boobs get covered more than not, yet there's that HOOTERS club... why don't they make a club for us foot guys called TOOTSIES or something?
5. That odd forbidden feeling you get!
Sure, most women think nothing of going around barefoot, yet most women act surprised the first time you give them a real good tickling or engage in toe sucking. (funny how most of them get turned on by having their fingers sucked tho... they won't admit it usually, but try it sometime.)
6. (and probably best) REACTION!
Let's face it, it's just not fun OR sexy if she's not ticklish. Also ,it's fun to indulge in the other foot-fetish pleasures (sucking, licking, etc) if it seems like she's enjoying it.
That's about all I could come up with for feet. Not that it takes the place of good, old fashioned, down and dirty sex... but it IS an enhancement. For me, it still excites me to tickle her nylon covered feet, even after 10 years of marriage, I STILL get all worked up, hard to catch my breath when I'm about to hear her mixed reactions (sighs and moans from the sex mixed with those sexy giggles... NOTHING beats that... for me, anyway).
I can pick no single event that led to my attraction to feet, it's just ALWAYS been there. Once, when i was about 7, my aunt passed out on our couch after a christmas party. I took her shoes off and spent about 45 minutes just touching her feet (she had knee-highs on, and she was about 23 at the time). It was fascinating, this was before I noticed ANY sexual ties to my love of pantyhosed feet, it was indulgence in it's purest form.
