One of my customers ran a karate studio. So the punks broke in (before I installed the alarm) and stole a number of things, including a pile of new uniforms with his logo/name on the back.....
 
How useless was that? It's not like you can wear them anywhere at all.  And if the karate studio owner/black belt sees you wearing his uniforms and knows you're not his student....... oh my....!!!
 
Free lesson you may not want....

I think you should wait until HE washes your shirts then, very calmly, walk over, open the washer door and take your shirts back.
 
What would HIS options be then?
 
(Then make a YouTube video of this one - we'd all have to see it!  )