Harlepolis said:

If we take it literally, she's pretending to be blind when his pants come off. Remember that scene in Private Parts where Howard gets in a bathtub w/ a model, but he leaves his underwear on so he's not "cheating"? Same thing in the song. But when his pants came off, she already knew he had left them on to begin with because he was "kinda seeing someone". So she gave him his modesty by pretending not to see what had happened. She respected his status of "taken". But then you could also think that he wishes she did make a move on him, because he was cursing her courtesy, by calling it a witch's curse. "Damn, I'm glad that she didn't make a move on me, but I WISH SHE HAD HAVE MADE ONE!" Conflict, like I said before. All conjecture on my part.