why bother getting involved in negotiations at all then?
Put your max offer in and you get what you want or you move on.
The point is to firstly never allow the EA to see if you're emotionally attached to the house.
Secondly don't let the emotional "one" of the couple do the bidding, there's always one.
Thirdly regardless of how emotionally attached to it you become no house is worth ruining the rest of your life for.
There's always another house you'll discover and by the time your a of an age or maturity of buying a house this emotional nonsense shouldn't be so extreme anyway