The three brothers headcanon which is basically Lily having three sons instead of two or one.

1) Milo (kmbell92 )
2) Harry (Second Oldest-twin)
3)' Blue' (Youngest-twin)

Guardians would be.
1)Minerva
2)The durlseys
3)Remus

I like the fact in this headcanon, they're all in different houses just-

1)Hufflepuff
2)Gryffindor
3)Slytherin

But yeah- that's one of my headcanons. I'll probably update more whenever I finish a book or others people have suggested.