If a girl isn't wearing shorts/underwear, and a guy is wearing two layers of damp shorts, can sperm travel through those two layers causing pregnancy?

Can't imagine: The plasma of semen creates moisture and if the two of your were "dry humping", some of your vaginal moisture might have made his pants damp. I can't imagine though that sperm could ever travel thru two layers of clothing and certainly as they hit dry air they become quickly immobile and die. I think you are fine. I wouldn't worry