In my experience, asking for "space" almost always means "space in which to conduct my affair, unencumbered."
How can you be sure there isn't someone else? She's certainly exhibiting most of the classic signs, and her sense of ENTITLEMENT runs DEEP, and that in itself is a huge red flag.
Although I would use nicer words, I believe everything Robx said to you. You'd be wise to listen to him.
How to address the mortgage issue? You call your wife, and you say "I need you to pay the mortgage. It's what we agreed to. Why do you think it is OK to pay for an expensive girls hedonism weekend, but not live up to your responsibilities?"
And then MOVE BACK IN TO YOUR OWN FREAKING HOME!!!
