What Causes Redness And Wetness Between Testicles And Penis?

i seem to have some type of infection in my genital area, my girlfriend had what appeared to be a yeast infection, she used monistat and it solved the problem. we were having intercourse during the infection and now just in between my testicles and the bottom of my penis is very red and wet, and a couple bumps have popped up on the shaft, what could this be and how can i treat it?