I have known quite a few bi girls. Allot of girls experiment a little and then give it up in the long run. I wouldn't worry about it but actually have her bring her g/f to your place for a night. Two girls are actually pretty fun just make sure they aren't little whores. It's popular for girls to try it out nowadays. Who knows maybe you can land both of them and get them both breeding for our cause. You'll have your own little commune......lol.