Depends whether it really IS bad. Or maybe you or she THINK it's bad. Check with the doctor: really bad smells often indicate an infection. If it turns out to be normal, then I agree with the first person's answer!
Hahaha at Headtime! Alot of sex can cause a bad Smell in the nether region. Especially if Condoms are not used. Stale Seamen is not a nice smell at the best of times. Have u ever been to a Penis Dr. Bobk??
She could have Bacterial Vaginitis (appetizing, eh?) which causes a foul smell even fresh out of the shower. If you've noticed any whitish lumpy discharge it could be a yeast infection. Or more severely it could be Human Papimalova (sp?) Virus which is actually a surprisingly common and curiously under-advertised STD. Don't go divorcing her, though, because it's easily cured. Good luck!