The fifth time is why I am writing. I know the first few times were very low risk, but the fifth time we did something different. We were both completely naked, I touched her buttocks and played with her breasts. This will sound stupid but I brought disenfectant wet tissues which I used to wipe her breasts clean before I began sucking on them. I also used these tissues to wipe her hands clean, she claimed she showered before but I did not trust it. After sucking her breasts for a while, we stood up and she used her breasts to masturbate me. There was a moment where she pushed my penis into her nipple several times. As it was dry, I took some oil she had on a shelf and applied it to my penis and continued on like this rather vigorously for a while, between her breasts and towards one of her nipples. Then she lied down on the bed, I spread her legs open to have a look but did not touch near her vagina. I then masturbated myself to completion. She may have touched my penis with her hands a little. I did not see her touching herself.

I felt terrible after doing this, I deeply regretted this and do not know why I engaged in this in the first place. I asked her politely if she had any std and she smiled and laughed at me, then said it's ok, it's ok, as her English was not so great. She made a hand gesture that suggests maybe she has some small problem, but she could not articulate it. Not once did any of the girls mouths or vaginas come into contact with my penis, I never put it in either. If they had secretions from themselves or semen from a previous customer on their bodies, I would not have been able to tell. I also did not open mouth kiss any of them. All of these women work in  a place similar to a brothel, in small stalls where many men frequently visit through every day. There is only one specialized STD clinic where I live and it's always booked, unless it is an emergency, I have to wait two weeks to see them(I live in Singapore). So I realize what I did was stupid, but I do not understand what kind of risks I took doing this. Can you please give me an assessment?

Also, I hope this is discreet and anonymous, when I registered I had to use my real name which makes me very concerned... :(

You have no worries about STDs. There simply is no risk from any of the events and exposures you describe. Without direct genital-genital, genital-anal, or genital-oral contact, STDs are never transmitted. There is no STD risk from kissing, hand-genital contact, or mouth contact with non-genital body sites, including breasts and nipples. 

So you don't need STD testing on account of these exposures. There is no possibility you caught anything. However, if you would like a reassuring professional evaluation, I'm sure you can find it without having to wait two weeks. Singapore has sophisticated medical experts and facilities, including some world-class STD experts. Contact the health department for information and advice. But I repeat that it isn't necessary except for reassurance, not because of any actual risk.

I hope this has been helpful. Best wishes--  HHH, MD

That will close this thread. Good luck.