Expert Q & A Answers About red bump penis

I don’t have signs of an STD, but my boyfriend just noticed a little red bump on his penis...what could this be?

This little red bump has appeared on my boyfriend’s penis, and it’s been causing him tremendous pain. We have been having sex for the past five months ⎼ he was a virgin and I’d only had sex with one other person before him. I have had no signs of an STD at all. Do you know what this could be? 

A bump on my genitals was red and then turned black. What could it be?

What if you have something on your genitals that starts as one red bump and then turns black...and it hurts?