Still bfing DS at 20 months (although it's had to fit around work since 8 months or so).
Not sure what you mean by "fusionnal"?
DH did a great job of bonding with DS, in fact in my darker moments I'm kind of jealous of the relationship they have.
I've never felt any sexual element in bf DS.
My libido definitely did drop until DS cut back to two feeds a day. I don't think it was just because of tiredness, so the bf is a candidate.
I do like the fact that bf means that when DS is in the right mood he gets worked up into a little paroxysm of giggly excitement at the sight of me. It'll give me something to remember when he's a moody teenager and doesn't want to be seen within a mile of me .