The sheet blanket thing

When my older kids were small I used flat sheets and fitted sheets on their beds....I soon discovered that making bunk beds with flat sheets is a nightmare.....so flat sheets soon were outlawed and we just used fitted sheets and blankets....much easier. Aaron and I were talking with Matthew tonight and he was telling us how hot he's been during the night. I asked him if he's using a blanket and he said "no, I'm using one of those sheet blanket things". At first Aaron and I were quite perplexed, I almost went to his room to see what he was talking about......but, then we both realized.....he has no idea what a flat sheet is....to him it's a sheet blanket thing.