I have a skin condition that i'm not sure what it is on my penis, i had unprotected sex with my girlfriend a month ago, then i noticed some redness and also flaky skin, is it std? or some skin infection? i have a picture i can show you

Penile rash: The large majority of penile skin conditions are not STDs, and these are not typical STD symptoms. If your gf has a vaginal yeast infection, that might be a possibility. This forum doesn't examine clinical photos. See a doctor, ideally a dermatologist. Or if you sign up for HealthTap's concierge service, a dermatologist may be willing to examine photos. In the meantime, this doesn't sound serious.