Have you ever worn chainmail without an undershirt? Or gambeson? It feels neat at first. Never had to worry about pinching. It didn’t grab any hair. The metal will feel cool and smooth all night. But oh Lord, the awful pain it will bring to unprotected virgin nipples. Like surfing for a hundred years without a rash guard all in one hedonistic night concentrated on the area less than two dimes. NEVER AGAIN. A couple bandaids or pasties the next time and all is good.
I think you’ll be fine with just a top sheet between you and the chainmail.