Say it ain't so. please.

A few weeks ago I got a new girlfriend. She's Bi. I've known this from the start. We just kind of clicked together from the very beginning and got even better as the days and nights have passed by. She has a on again/off girlfriend who I've met. All of the cards are on the table here. I've asked my new girl to move in with me. She might as well. We spent all of our free time together. And I sure could use. a roommate to share the rent. We both have good paying jobs. The problem? She wants to know if it would be cool with me if she spent a night or two every week with her gal pal. She said she needs time to break it off. Say what? She says its different with women. Breaking up. Am I being played for a sucker? Is this how gay women do things? I've seen that question asked recently on this site. I have no idea what is normal for lesbians. And our relationship is still kind of new. Her having sex a couple of nights a week with a woman doesn't really bother me now. But it will.