I don't know if anyone has any ideas about this but my partners t-shirts get small holes in the front of them.
At first he put it down to his washing machine, but it has happened again with a new t-shirt that has only been washed in my machine (I have no problems with my clothes) so it doesn't look like it is the machine. He hasn't been wearing a coat lately because of the weather, so that knocked that theory on the head.
Any suggestions gratefully received.