Stealing

When I got dressed this morning I do what I usually do. I grabbed something out of my closet and took it on. Felt a bit weird though and I couldn't remember when I bought the shirt. But since personal shopper makes me buy lotsa things, I figured it was one of those tops. All day it felt weird though. The shirt was a bit long, and it flattened my boobs. Very odd. Until it just now dawned on me. Could it perhaps have been former flatmates shirt? And when checking, sure it buttons on the other side. He was skinny and tall. Fucketyfuck. Can this be classified as stealing? I surely didn't mean to. Must've gotten mixed up in the wash. Guess I have to contact him and ask, don't I?