A little background. I'm a 19yr old male with only one partener who I lost my virginity to 3 years ago. Sex has been great through the years until recently.

Within the last 3-4 months, I get intense cramping in my pelvic region during intercourse. At first i'm fine, but after a few minutes I feel it tightening and its soon almost too painful to walk for a short time. I've searched the internet over for anybody else with the same problem, but anytime I key in 'cramps,' women's sites flood the browser.

Masturbation and oral sex doesn't cause the cramping, just prolonged intercourse. The pain is in the area above the base of my penis below the waistline. I've wondered if the cramping is caused from me holding off orgasm and it stressing a muscle or something.

Any feedback on this would be greatly appreciated. There is no rashing, leaking, burning, etc that would lead me to believe its an std.

Thanks.