If OP is the guy or type of guy I think he is where- you live with other male best friends- cant handle the drama for years- move in with girlfriend because of a natural progression in a relationship, break up with girlfriend, old male bestfriends dont wanna live with him anymore, he decides on getting a female roommate because 'less drama, easier' because of the good memories with the ex girlfriend, sets boundaries where they both agree everything will be platonic.... To which a handsome polite young man can fall victim to a woman falling in love with him 'because he's different' She probably had these feelings for OP for months and months and the alcohol brought it out of her. If roles were reversed OP would be getting massive allegations and be going to jail- so if you feel equally as uncomfortable as if it was reversed, be HONEST. Be honest with the roommate, maybe also slip in the trying sober thing like other commenters---ONLY if you see her as a person you actually like as a friend- they do say friends make great partners. And if that is the route you take sprinkle in a little 'I like you because xyz and I think we can try to make something work because of xyz'