So (s)he pisses you off. Majorly. You raise hell and send him/her off with a warning never to call you again, text you, or come over to your place ever again. But you're certain (s)he'll do one or all of the above, because 1) it was not your fault in the first place, and 2) anyone in their right mind with any regard for the wronged party (and any of the love they profess) would do everything in their power to make it all right. So you wait.
1) Pride comes before the fall.
He's prouder than she is. Or she's prouder than he is, or they are both way too proud for their own good. None approaches the other, while each waits. A stand off ensues, especially if it's not possibe to pinpoint with certainity whose fault it was. The wait continues, and if none eventually comes around then that would be the very probably unforeseen death of the affair, and a true testament to pride coming before the proverbial fall. Goes without saying there would be tonnes of regret on both sides. Unless one of the two is a cas of 2) below.
2) (S)he's really not that into it after all.
The harm has been done and each party goes off to leak their wounds, and ofcourse to wait. Ofcourse the wronged would be perfectly right to wait, because that's what's done, right? One waits for the apology, that's what one does. And, ofcourse, which ever peace offerings maybe laid at the altar of contrition. Well, along comes a shocker when nothing is forthcoming, not in word, deed, or act - simply because the relationship doesn't mean as much to the sinner as it does to the sinned. (S)he may have been waiting for an opportunity just as that, with tempers flaring high, to make a scott free escape. It would be the perfect excuse: they wronged you, you got mad, an altercation ensued and each party stomped off. With one party heaving a sigh of relief, the other hurt. If the wronged party sees nothing forthcoming from the other, has some sense of self-worth and believes they are not that valued, then that's the end of that too. Unless ofcourse the wronged party is a case of 3) below.
3) (S)he's really not that into it after all, but you really can't let it go.
Now and then you find someone who takes the meaning of the age-old adage 'Never give up' to a new level. This person has mastered the art of perseverance and honed the craft of determination, and so they do just that. Persevere, determining never to give up. And after waiting for a while for the never-forthcoming apology from the not-that-into-the-relationship party, this perseverant sinned-against brings matters to a head, lumps it, goes upto the uncontrite sinner and says 'You know what? Let's agree to disagree. Let's forget it, make up, and move on" and what choice does the other party have but to make up (giving credence to the 'never give up') or belt out 'You know what, NO! I'm really not that into you, let it go!' And really, what are the chances?
I've got to say I always have some pity for the perseverant category 3 folks. I seek for value in reciprocity, and when it's not forthcoming I for one would feel cheated. So back to our question, when it comes to eating humble pie who should go first, it goes without saying that whenever someone does wrong they should have the decency to own up, and make up for the wrong. I've not yet found any acceptable exceptions to this rule, have you?