She thought it would be funny...
I once lived with a woman who one day thought it would be funny/embarrassing to give me an erection in the middle of a mall parking lot. I as wearing knit sweat pants and no underwear, and when we parked the car and got out she decided it would be fun, while we were hidden between cars, to reach down and start rubbing my crotch, giving me a pretty instant erection. BUT, she figured it would be good for a laugh and that I'd try to hide. Instead, I put my arm around her, held her close, and walked us both out from between cars and into full view and headed for the mall entrance, my erection proudly pointing the way against that soft sweat pants material and she trying not to look embarrassed by the situation.

