Try this trick. It really works and gives you a whole different sensation. Rub your penis to full erection. Now, using a blue menthol gel (found in pain relief gels and ointment section of the drug store) or menthol cooling Aloe Vera Gel, put some on your fingertip and put it directly on your anus. You can also try inserting some of the gel on your fingers in your anus. The warm, burning sensation will really make your anus feel tingly and warm, and sends really nice extra stimulation to your erection. In fact, you will find that you will be able to maintain your erection for a longer period of time.
This can also be used to enhance your love-making, too. Just put a dab of gel on your butt-crack, and during intercourse, when you feel yourself lagging, reach back and spread the gel over and inside your anus. Your cock will instantly turn rock-hard, and you will be able to rock your gal for even longer.
Note: The gel feels nice when you spread it all over your balls too, provides a nice hot-cool sensation at the same time. Not so nice directly on your cock, because it can get into your pee hole and that does NOT feel so good. So try my tip, you'll definitely like it!