Hello. Thank you for writing to us at healthcaremagic I suggest a possibility of furuncle/boil, which is a bacterial skin and soft tissue infection; the infection gaining entry through the hair follicle. Pain and swelling are part of a furuncle. I don t think it is in anyway related to your sexual activity. If I was the treating doctor I would have treated you with a course of an Oral antibiotic for a week. My choice of an Oral antibacterial would be either flucloxacillin or a cephalexin for a week. Oral antibiotics are prescription medications and I suggest you to talk to your doctor for the needful. Topically I suggest you to apply an OTC topical antibacterial e.g 2% mupirocin ointment, twice daily. An OTC Oral pain killer e.g ibuprofen will provide you symptomatic relife from pain and swelling. Regards