I am 37 Yr old. For last 3 weeks, I see a patch on the tip of my penis (on the left side just below the urinal opening) as if the skin on the tip of the penis is removed in that area. There is no bleeding or opening of internal mass. I also do not have any pain or itching at the area of the patch. I masterbate heavily, often rubbing my penis on the bed while wearing the underwears. Before I observed this patch for the first time, I had masterbated heavily rubbing against the bed while wrapped in a turkish hand towel. But, I am not sure if the this patch on the penis is due to the my penis getting hurt during such masterbation. I am conncious now while maserbating as the patch on the penis becomes wet due to my precum durng masterbation or gets red due to rubbing action and looks as if it will blow up / open up. I have also had oral sex and intercourse (both protected) with an unknown partner exactly 4 weeks ago (I am observing this patch since last 3 weeks, but also not sure if it existed before that). The intercourse was't complete upto the point of ejaculation as we stopped in between. The sex partner had blisters in mouth. We have exchanged saliva while kissing. The oral sex (sucking of penis) was also with condom. Also, I have rubbed her vagina with my bare fingers. She was wet and discharging precum (natural lubricating fluid) while I was rubbing her clitoris and vaginal opening. Apart from this patch on the penis, I do not experience any other abnormilities. I have got blisters in my mouth for last 3 - 4 weeks. But, I often get mouth blisters due to acidity if I do not sleep properly. Please advise if I need to undergo any particular STD tests or HIV Test or se any medical advice.