The groin area sweats and can give out the smell of sweat. This should go away after a good bath. This is normal. But, if the smell is foul and strong, then that indicates a medical condition such as:
a. Urinary Tract Infection
b. Yeast Infection
c. Balanitis
d. Gonorrhea
e. Chlamydia.
You can suspect Gonorrhea and Chlamydia if you had unprotected sex with a new partner. You have to talk to your doctor as soon as possible and get tested. It is important that your partner also gets tested and treated.