Perhaps this discussion can be handled using game theory (is that the worst pick-up line ever, or what?). If you consider 10 to be the best, and 0 the worst then (IMHO):
Together, Happy = 10
Single, Happy = 7
Single, Lonely = 3
Together, Unhappy = 0

The game theoretic problem is for the Single at 5 to decide to gamble for either a 10 or a 0. The Single at 3 is haunted by 0, but is urged on by the prospect of 10; the Single at 7 has no incentive to go for a 10 when 0 is a big possibility, and so on. I was given this theory once on a cocktail napkin by a very unhappy woman who had been unhappily married to a mathematician. (True story!)
I add it here so as to bring order to a messy situation, also known as life.

Yours, Peter T.