This is one of the initial hints that Buffy has the hots for Xander, but even with that resolved, I'm seeing something more in it. In #33, after Buffy barrels through the tower and into Twilight, he tells her, "You're even stronger than I'd hoped. That was the first blow I've felt in a long while."
Does feeling decrease as strength increases? If so, it looks like Buffy and Angel are now so powerful that they can't feel anything except each other. Applying the same principle to emotional feelings as well as physical sensations could even explain some of the more bizarre turns that this issue took.
Not particularly romantic, but I could see it coming into play once the greater meanings begin to be revealed.