I would like to know how safe body to body naked thai massages are. Specifically for herpes and syphilis. Not penetrative oral or vaginally sex occurred. 

I have had a few naked massages at parlors and this week few days after a recent visit I developed a burning feel near me inner left thigh going down near my anus. That is the only feel I have had. 

Could the burning rash be secondary syphilis or herpes. I say secondary as incase I didn't catch the primary stage initially from one of my older visits? 

Body to body rubbing/massage (sometimes called "frottage") is considered safe sex.  Certainly without penetration there is no risk for gonorrhea, chlamydia, HIV, trichomonas, etc.  On the other hand there is a largely theoretical risk for acquisition if a partner happens to be infected there is direct contact/rubbing with a herpes or syphilis lesion.  This concern however is largely theoretical  Typically the skin on the rest of the body is less vulnerable to infection than genital skin because it is thicker and less sensitive to transmission than genital or mucosal skin.  When you combine this with the fact that most commercial sex workers do not have STIs the risk of infection is miniscule and typically not something to worry about.  This opinion is shared by the CDC, the WHO and most professional organizations.  Most experts do not feel the need to recommend abstinence or testing after such exposures.

The burning sensation you describe does not suggest syphilis or herpes.  The rash of syphilis is typically asymptomatic and the rash of herpes is typically small blisters containing clear fluid and is uncomfortable butn not burning.  The symptoms you describe could be a fungal infection (the area you describe is a typical place for fungal skin infections).  If lotions were used for the encounter, sometimes they elicit a burning sensation as ell.

I hope this information is helpful.  EWH

1)Is it safe to assume this is not an std cause across all stds.

2)Can std symptoms return the way this is occurring. I felt absolutely nothing yesterday and this morning I woke up and felt a slight light inner thigh burn. I reapplied the cream this morning to stay on the path for applying an OTC cream for it.

Thank you

1.  Yes, there is no reason to think that this is an STI.

2.  The symptoms of STIs, including HIV, do not come and go.

Hope this helps.  I urge you to move forward from here.  EWH

Safe to proceed sex with my regular partner.

Thank you and this will end the thread. 

When I tend to walk or do am activity I don't feel it as much vs when I sit/stand still and I wonder if it is because my mind is racing.

Thanks

In answer to your other question, it is safe to resume unprotected intercourse with your regular partner.  there is no risk of having an STI which you might transmit.

Hope this helps.  Closing the thread shortly.  EWH