TMI vag/anus please help!!

Alright y'all, here's the backstory.

I've only ever slept with one guy, and he has only slept with me. I'm 100% sure of that bc our first time together was SO awkward neither of us knew what to do. I'm shaving today and shaving a little more than normally and see this brown/purple thing. Idk how long it's been there either. It doesn't hurt/itch/burn either. Any idea what it could be? I wouldn't have known it was there if I didn't take a mirror & shave lower than usual.