I recently gave my boyfriend oral sex and I felt a rash on his penis however it was not visible to the eye. What could that be? I recently gave my boyfriend oral sex and I felt a rash on his penis however it was not visible to the eye. What could that be?

There. There are different possibilities. Herpes or genital warts could cause a rash you could feel. Please be seen and have testing if you have any symptoms at all. You should also ask him about his rash as he may need treatment as well. If you have any lesions, pain, discharge, fever, or vomiting, you would need to be seen immediately.