She probably pissed herself, sweat all over herself, or was emitting some horrifying odor. Possibly all three. The guy looked around and determined the source but was too polite to make a comment. How that became sexual in her twisted mind I have no idea. I've been checked out plenty and never once have I noticed a guy staring directly at my crotch. Breasts, ass, legs, mouth, shoulder/neck, even feet but not vagina. Men tend to intentionally avoid staring at that body part because there's no plausible explanation if they're caught.