Yeah, all you see is a close up of her face reacting, it's pretty hot. Very quick. There's obviously a setup for it, as well, as if she knows he's about to do it.....she's smiling flirtatiously and in total anticipation, he prepares himself by sort of adjusting his hair in a goofy way, then bends down out of frame and then....."EEK!" giggle. I wouldn't be surprised if he had perhaps seen the "I love to be tickled" quote and asked permission to tickle her. That's kind of what the vibe of the clip appeared to be. Hard to tell.
Even though I have it somewhere on one of these videotapes of mainstream, I doubt I'll ever digitize them, they're probably all going to be in the garbage soon; maybe someone else has it, though. It definitely was traded back in the day, which is where I got it. I may have even gotten it from TMFJeff! I know I traded mainstream clips with him a couple of times, in the early days.