The very thing the man was most trying to avoid - his girlfriend cheating - by having his girlfriend spend less time around other men and her friends is the very thing that he basically creates by cutting her off from her sources of joy. By reducing her positive sources of happiness he drives his girlfriend to find maladaptive, non-constructive sources of happiness. 

...of course, the wonder of it all and the endless tedium of those who drone on and on about ‘untreated depression’, “I’ll be there for you if you’re considering suicide”, and all the other overwrought blather.

Suicide.

I mean, we’ve all thought about it, at one time or another...

It is one of life’s ugliest, yet most beautiful paradoxes: creation and destruction are forever inextricably dancing; pain and joy live in the same breath; blessings and curses can never be extricated from their mad embrace. We, it seems, need only have the eyes to see, and the courage to look into the eye of the beast that afflicts us at any given moment or period of life.

Ask yourself one basic question. It’s not the cure-all question, but it gets us in the ballpark. What do you do when you’re at Starbucks, after you’ve ordered, and waiting for your drink? Or, for church-going folk, perhaps while you’re standing in line to exit the sanctuary at the end of service? Or, when you’re standing on the platform waiting for the subway? Or any line anywhere, or anytime people are around? Why?