I mean, that could happen in the original if your best friend was the opposite gender. Better solution is to just be able to enable/disable romantic relations on a mii by mii basis

And if they don't add that, either just remind yourself it's just a silly game meant to be random and chaotic, or just don't add real people you know

You could prob make Miis hetero, homo, or bi

i think there'll be an option to choose the mii's sexuality because it would be weird if they just let them fall in love with whoever

just... have the miis reject each other... like the straight ones do...