Two days before I dropped in a gay club very occasionally. There was a sexing party (many gays having sex) at that time.
I have not involved in but just watched aside. Then a man came to me pat on my chest with his palm inviting me to join.
I have found his palm was very wet and I was not sure what was on his palm (whole palm wet). I could not smell semen from what has been left on my skin but it seems not to be pure water (a little sticky). After the liquid dried on my skin, I did not feel tightened or something dried on the skin (which might mean there was not much protein as pure semen). I guess it is a mix of lubricant, sweat and some body fluid.
The problem is that where he patted on me, there is a small boil(red sore?) on my skin (2mm), which was not a very fresh one at that time. I am not sure whether the top of the boil(red sore) has broken or not. At least when there was liquid (water/sopa) on the boil, I could not feel any irritation. I have uploaded a picture for a reference for you to check what it looks like. http://s28.postimg.org/z19uqjhbh/boil.jpg
I did not do join them and left a little bit later.
Could you let me know, do I need PEP or testing for HIV, please?
Thanks.