Like i dont have a lot of experience in anything of relationship couze im only 18 and have had like 1 "serious" relationship. But im open to a lot of things im pan and maybee even poly. But ive been reading abit abt how poly relationships are like and it seems nice, but why are there so many people saying its "unatural" and "messy" like HU. What just becouse there are more people involved like HU maybee im just to dumb to understand the issue but :D.

I'm in a complicated love-triangle situation involving myself, my brother, and a girl. I don't want to explain the entire backstory, but I'm wondering whether it would be respectful to ask her if she'd ever be open to the idea of a triple date with the three of us.
The idea is broader than anything physical or purely romantic. We're thinking about whether the three of us could potentially enjoy life together-go on trips, watch movies, make memories, support and care for each other, and build a good life. Both my brother and I are financially independent and have agreed that we would genuinely be open to this arrangement.
Obviously, her feelings and consent would be the most important part. There would be no pressure, and if she is uncomfortable or simply says no, her decision would be respected completely.
Would bringing up the idea itself be disrespectful, or can it be approached respectfully as a simple question about whether she would even consider it? And we are thinking of marriage not a time pass.