I'm dating someone who's bigender, and I fell for her from the moment we met. We're very much in love, but... I can't seem to get along with the other person in the dynamic. They're just... so different. On the one hand, she's caring, funny, responsible, submissive, and someone I trust completely. On the other hand... he's hurtful, childish, he taunts me, and he's an incorrigible flirt. He doesn't seem to actually take seriously anything I say, and has previously ignored or sidestepped things I bring up by telling me that it was her I was talking with, and that it doesn't apply to him. My latest interactions with him have usually culminated in heated arguments-- I can honestly say that there were times when I wished he didn't exist, the fights got so bad.
I feel like I'm at the end of my rope... I love her desperately, but he's someone I clash with so much that I don't think I could even stand to be friends or acquaintances with him. The complete shift in demeanor and personality is just so... jarring, it makes everything seem unstable, and when he's so defiant and argumentative, it makes me question the relationship... how or if she can still want me if there's so much enmity between he and I, whether he's conspiring to break us up, how aware she is of what he says and does... it's just all so confusing and disorienting.
Am I a terrible person for having these concerns and problems? Does it mean I just don't love my partner enough? How can I learn to get along with him? Is there any way to influence his behavior for the better? Or am I just not cut out to make this work, and if so... is it possible to be in a relationship with just one of them?


