Just watched a Next Generation episode, First Contact. Great!
Riker has been injured and is being held against his will on an alien planet. One of the aliens (played by Bebe Neuwirth) offers to help Riker escape, "I'll help you get away, but you have to do something for me. I've always wanted to make love to an alien." Riker's eyebrows go up and the two walk off together.
Fade to the next scene where the alien woman is peaking out of a door to see if the coast is clear. She has a big smile on her face while she adjusts her glasses and straightens her hair...
Wish I was an alien!