My boyfriend's penis was a little red and began to sting...

Last me and my boyfriend had sex, when we where finished, he said his penis was stinging a little and half of the tip of his foreskin was red.

The stinging stopped after a while, and he slept without boxers on to cause less rubbing, this morning it was still a little red but didn't seem as bad as before.

I had a UTI and cystitis in the last month. BUT we always have sex with a condom, so I cannot have passed it on. (We're also both clear on STD's)

He's a little worried but doesn't know if he should be worried enough to visit a doctor. He wonders if he's "over used" his penis as he said since we started dating/having sex he does find himself masturbating more when he's alone.

I wondered if it was just dry (skin has looked dry and flaky) and there for when he masturbates or has sex it just causes some sort of irritation, and if he went to the doctor would they suggest the same thing and just give him some sort of cream?

We'd love any suggestions you can give before we go and bother a doctor.