@bernsky,
Familiarity sometimes is misinterpreted as love.
Why am I saying that? You were on and off, on and off, due to some BS. She, goes off with your best friend, gets pregnant and decides to marry him but it's not what she is after.
Where you what she was after?
He is not what she is after?
Does she know what she is really after?
You can "love" your best friend but if you sit back honestly and look at that roller-coaster and her, reeling you in, letting the line go, reeling you in, letting the line go..... You may actually see a different picture.