How to Deal With a Manipulative Roommate

"It's getting boring here. Can you guys go with something new?" "My roommate of five years has this new lady who is cool, but off the bat seems kind of manipulative," he says. She wants to move into our two bedroom apartment in New York City for three months. Do I accept the cheaper rent or tell it to take a hike? By the way, they've been dating for six months. You rule go fuck yourself." 'There's not enough money in the fucking universe for me to compromise my quality of life'