My boyfriend and I dry hump very often. He is naked and I keep my pants on. We both come but when he does he puts his hand on his penis or it comes on a towel .Is there a any risk whatsoever that his sperms find their way into my vagina if we dry hump again...i mean while my jeans are robbing on his penis that ejaculated before? Is it better to put on jeans rather than thin sweat pants? plz help ASAP! Thank you!