Well for starters, if you consider yourself weird, others will consider you like that too. There is nothing weird in tickling. It's how you introduce it. Like with sex, you can't just expect a girl to hop into bed with you. You have to do it slowly, get her to like you. Same is with tickling. Introduce it slowly and be respectful of her. Don't get all creepy, introduce it as your slight kink, and don't immediately start with intense foot tickling.
For example, start by slowly introducing bondage. Tie her lightly, as a form of foreplay, but don't do anything tickling-like yet. Just make her feel good in those bonds. Then, once, make a romantic atmosphere, turn off the lights and fire up some candles, placing them around bed. Give her a slow massage, all over, sneaking in a few tickles. Then, take out two feathers and slowly, gently and passionately start exploring her body with them. Let her enjoy it's touch. Mix in tickling and pleasure, enjoy her light giggles, don't push it. Just do it slowly, gently, give her a time of her life. She should slowly start opening up to tickling in that way. Then, you can push in foot-tickling. Of course, all of this is under the condition that the girl is a nice person and likes you. If not, what are you doing with her, then?