I know one of my gay friends says that they're more hesitant to date bi people because if things get rough when dealing with the backlash of being with the same sex they can use being bi as an excuse to pursue a more "easier and accepted" relationship
As a bi individual nothing gets on my nerves more than this mindset. You don't just choose to be in a hetro representing relationship because you want things 'easier'. It's so ridiculous to assume that and is why bi people get so much shit from the LQBTQ+ community. We're not more likely to cheat, to want threesomes, to 'act straight when things are tough'. We're human beings with very individual personalities. I think your friend should re-evaluate their prejudices
He doesn't just "assume" it tho, his first bi boyfriend left him when he got shit from his parents about dating a guy. He knows not all bi people are like that he's just really cautious about it now
if you’re bi and leave your gay/lesbian lover just because they can’t have kids you’re the worst. you went into that relationship knowing that. that’s just like you were playing them from the start. also kids are fcking annoying