It may just require mentally focusing, to re-hardwire your brain yourself to enjoy the real life aspect of it more. Because it's a fantasy, you may have developed walls in your head that you're not aware of, that you'll have to break down yourself to get to that next level.
When it's a fantasy, you have no restrictions. There's no human there to bounce off of. You subconsciencely know that when a real person's there, they may show disgust, revulsion, be a bitch, say they don't like it, etc. This will destroy you, because even if you THINK people will say that about you.....they haven't really, so there's hope that they'll be totally accepting of you. If you actually HEAR it, there's no denying that reality and it'll kill you unless you have a stomach of steel.
This is why so many guys will dream of asking the hot girl out, but never do it - you can always imagine she'll say "yes," even if you're sure she'll say know. There's always hope. If she actualy tells you NO, ....ouch! You can't deny the hard cold reality.
And these thought processes will always be there, even if you have a willing ticklee. Maybe you're afraid she'll react once in disgust, and then it's all over with.
I've always been impatient with guys or girls who will end a great relationship because their partner doesn't like tickling, but I've softened my stance after realizing that yes, that is one hell of a kick to the gut, and a fundamental pain/let down/attack on you when they attack or are repulsed by something that's a part of you you can never change.
You're very, very lucky to have met more than one willing 'lee...who WAS ticklish.
Since you're so lucky, don't keep losing them!
The mental processes I'm talking about are similiar to the ones guys or girls use who have strong fetishes, and must get past them in order to have normal sex. Some guys can't have sex with out tickling at all, and must eventually learn to focus and have normal sex, or they say alone unless they happen to find a woman who will tolerate being tickled EVERY TIME they have sex.
I mean fair is fair, and at some point, unless she is falling on the floor-can't think straight when you're around-gets excited when your name is mentioned-in love with you! she will at some point just want regular sex.
And on the same note - there are plenty of guys and girs here who ONLY want the real thing! Hopefully they'll chime in.
For example: for the pantyhose/stockings lovers, there's nothing like feeling and seeing a girl in pantyhose and tickling a girl in pantyhose to watching it on video. The bare footers are probably the same way. The senses go into overload with the real thing, and maybe that's why the reality isn't so hot - your brain can't process that much info, so it kind of shuts down, and you're sitting there thinking "ehh, that was alright...."