Opinion: do you think this concept is weird?

I’m just curious on people’s opinions on this sort of thing: a poly (?) romance story with three people involved, two of them are identical twins and the third person is unrelated. The twins are NOT romantically involved with each other at all, they just both have a relationship with the same person (and everyone is aware and cool with it). So it’s one unrelated character who is dating two twins at the same time. Is this immoral or strange for a romance story?

And if anyone is wondering, I’m not writing a story with this myself, but the premise just crossed my mind.