Tiki Barber is the RULE

What makes a "happily" married man with kids blow demolition charges beneath the foundation of his perfect life, blowing debris of hurt, shame, and humiliation all over family and friends?

New pussy, is what.

Tiki Barber had a perfectly decent pair of shoes (currently eight months preggo) that he'd worn well for eleven years, but he suddenly saw a pair of new shoes (in pic, above) and had to have them.  You ladies know that feeling, right?  Staring at those designer sandles, wondering if the financial risk justifies the reward.  Fuck it-- you need those shoes!

Men look at what's going on with the former NY Giant turned sports "journalist" and we fully understand, even if we pretend to agree with your suggestion that he commit hara kiri.  Tiki wanted some strange, he wanted it young, and he wanted it no farther than his reach.  Men, especially those in positions of power-- don't know if being able to call Jenna Wolfe a cunt during the Beijing Olympics qualifies-- take full advantage of their clout and celebrity but still only pursue women in their immediate universe (see Clinton).

So could your man pull a #21?  He's probably more likely to.  Tiki Barber is rich and handsome and can get all kinds of hot ass.  Your man was lucky enough to get you (and a dimepiece you probably ain't).  He likely earns a mid to high five-figure salary as the bottom bitch at XYZ Corp and pines for summer when the college interns arrive like manna from heaven.

[Postscript: Even dogs know not to shit where they eat.  Tiki's kids, as opposed to Tiger's, are old enough to comprehend the scope and consequences of what he's done.  For a man who said he couldn't forgive his own father's infidelities, Barber will now have to bear the potential filial wrath he's long carried within.]