Has anyone had a rash like this before?

I have had this rash on my inner thighs (both sides) for a few

months. Sometimes it is less red and more brown. It doesn’t itch, it isn’t raised, it really doesn’t bother me. However i cannot find anything online that looks similar. Anyone ever had it before?

A nurse said it could be from my thighs rubbing together?

Thank you!

(The big line is from my clothes not the rash)