Okay so like a week ago this showed up after sex and it's between my boobs. It feels like a burn so the only thing I can come up with is that it's from being on top during sex and my SOs beard rubbing my chest and me being so in the moment that I didn't realize it. It went away but it came back worse last night after sex and it hurts so bad. I tried putting neosporn on it and it burned REALLY bad. What do I put on it to help?? And next time when I'm on top I'm wearing a shirt because F this! 

Update: I tried lotion and it burned so bad I had to wash it off. I talked to my mom and showed her and she handed me diaper rash cream and it's helped tremendously like it's already started to heal. Thank you for your help guys.