My bathroom door was squeeking, so I used some WD-40 on the hinges. The squeeking has now stopped, but now the bathroom door doesn't want to stay open and slowly closes. Does anyone know what I can now do to the hinges to make it stay open? Thank you !

This is an old trick I've used in the past.
Remove one of the hinge pins and put a slight bend in it. (I put it in a vise and give it a couple of light-medium whacks with a hammer.) You don't want to deform it, just put a little bend in it. A more controlled approach is to put it in the vise and slip a small pipe over the pin. Use the pipe for leverage to bend it by hand. Remember... do not bend it much!

Put the pin back in the hinge (you may have to tap it with a hammer), and the added friction should stop the door from closing.

Hope this helps,
WallyH