Why does my partners penis get super itchy after we have sex? were both free of stds. we also dont use any condoms or lubricants?

Dry skin on the penis, rough sex, or sex without enough lubrication could cause friction burn and result in an itchy penis. If these conditions are ruled out, I suggest using condom as a trial. If he is not itching after the intercourse, I would wonder if his penis is allergic to your vaginal substances. However, itching vagina due to semen is more common.