Frequent Guest - how often is too much?

So my roommate met who is now her "new love" 4 weeks ago. While I like this person, she keeps inviting them to stay overnight, and its getting a little stressful. The routine seems to be they both stay here two nights, take a night off, and then are together the next two nights, etc. What really irks me is they could just as easily stay at the other person's apartment - this person lives 15 minutes away! They have only not stayed here one night in this entire time.

To add to it, since meeting this person my roomate has become very sloppy around the apartment - she took out the trash and did the dishes one time this month, both times I had to ask her twice to do so. She never cleans up the living room , bathroom, or kitchen, but whenever she has company, she always makes sure HER room is tidy. So I'm running around trying to keep tidy, and then when we have company, since my bedroom always comes last and I can't keep up on a 2 person mess by myself, I look like the slob. It doesn't help that aside from guessing routine, I rarely get a head's up when there's company coming over.

I want to say something but my big hesitation is my boyfriend stays over usually 2-3 nights in a row as well. However he and I have been dating for almost a year, and I was living here with him coming over frequently before I asked this other girl to be my roommate (mostly just to cut the rent down and she was in a bind with nowhere to go at the time). I even talked to him and told him he needs to give me a head's up when he is coming over, to be polite to my new roommate.

I have also explained to her that my boyfriend lives an hour and a half drive away. I work 6 days a week at 8am to 6pm so its not really possible for me to stay at his place unless its the night before my day off; his work is a lot more flexible. He also isn't over as frequently - he will come and stay for a few nights and then go back to his place for a week or so. He also as of late has been doing dishes and helping tidy up just because he's great like that and knows I'm getting really stressed about my sloppy, lovestruck roommate (she's 25, I think she'd be old enough to have a little more sense...)

So do I have the right to say something? I just feel like when I invited my friend to live with me, I was asking for ONE roommate...not TWO. I know we're both adults and we both pay rent and should be able to live like adults without having to report to each other, but at the rate this new relationship is going I'm concerned if I don't speak up, soon I WILL have two roommates permanantly!