This guy really knows how to tease with his ass. He wants it bad. Pushing his big soapy manly ass out and rubbing it with soap and then sliding his finger deep inside. Horny.
One of the best places to finger a guy's ass is in the bathtub. Get him all naked and soaped up. Make sure he's squeaky clean paying careful attention to wash his ass crack and his sphincter. Then rub that hole slowly until it's nice and relaxed and slide your finger in with the suds still sticking to your fingers for a nice long male asshole fingering session.