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From the picture that you have sent, it doesn't look like any STD. Moreover they have been there for quite a few weeks, and STDs by this time would have manifested with rash and fever. Can you give me slightly more history if you had any such exposure to contracting STD in the recent past? And it is definitely not genital herpes.
These look more like boils. For some people with extremely oily skin, and also considering the fact that the area is sweaty, it mostly points towards a boil. Sometimes a lot of oily secretions get clogged up and manifest in the form of such small boils. They can also be caused due to infected hair follicle, can be due to excessive sebum deposition. I will advise you to apply warm water compress over the affected area, ( don't squeeze it at any cost ) , a few times a day for the next few days and see if they are resolving. Avoid shaving for the next few days, and if possible apply Benzoyl Peroxide gel in the affected area, after cleaning with betadine solution.
If it is not resolving by these methods, it is better to consult a dermatologist, who can examine the bumps directly. Sometimes these bumps can indicate a viral infection ( Molluscum Contagiosum ), and in that case it can be extracted with a needle.
Hope this helps. Please post additional queries if you have any,
Regards