I had a skin tag on my butt. I had it for about a year and it didn't really bother me until today. I took a nice shower and when I got out and dried off I noticed it inflated. It cant be sex related because i havn't had intercorse in over 2 months. It was little and flat the other day but today it has seemed to swell up and is shiny and big. I know I should see a doctor but I work 60 hours a week and would rather put it off until next week.
Make an appointment for the doctor for next week, in the meantime you can watch the spot to see if it has any improvements, but I would get to the doctor to have it checked out.