My ex girlfriend's girlfriend is doing her wash in my wash machine and stealing my detergent and not even paying for it. What should I do?

Throw her in the machine and close the lid. Problem solved.

You should get your act together.

just tell her she cant use it

Lol Oh good idea

Change the locks??

You just want us to know you had a girlfriend so, you are telling us this story, I KNOW.  Is she pretty? Put battery acid on her scalp.  Show her what you are made of.

In the laundry room of my apartment complex someone kept stealing my laundry detergent.  Granted, I use the cheap dollar store brand so it's not about the money, it's about the principle.  That's why I took a bottle of detergent that was only about 1/4 full, filled it up the rest of the way with bleach and left it there for the thief.  I just bring my detergent down with me whenever I do laundry. 

As a one time thing I wouldn't worry about it.  If it becomes chronic then it's time for dirty tricks. 

But she does my laundry too.

Go round to her house and steal her detergent in return. That's what I would do. Lol:)

Stop paying your electric bill. Muhahahahahah!!!

just loose your mind at her

Her doing your laundry is compensation for using your machine and detergent, no?

brutal man.

Tell her to stop.