My girlfriend is actratted to brest and makes out with other woman is she bi? She says no! Is she?

She says I am insencetive because I dont feel she is being true to me or her selI just dont under stand every think i LOOK UP SAYS SHE IS. she says shee likes bres but not the resst. thats fine but i that sill bi right? The reest seems like clic case of adult confusion and female biuality guilt syndrome I dont wont to be rude to here feelins buti dont want here to think I am A *** for not agreing with her? wath would a ologyist say? I was trying to hellp here and now she hates me I dont undersand!