Hi young man .... Very well observed by you. The loose and wrinkly skin mean these are overhanging testes. When you are involved into kissing or lovemaking there is contraction of the abdominal muscles with pulling up of the testes( this is normal for all males). But at the same tine there is twisting due to a particular architecture of the muscles attached deep inside the scrotum. The easy way is to support your scrotum with lungot (sort of a triangular clothe which wrestlers use) or briefs. No strain on the abdomen. Please let us know if this simple maneuver helped you.