|Yeah, secret-baby is a pretty solid reason for a divorce. Source|
What to Expect: Lots of denial and pure, crystallized rage, top with a whirlpool of accusations that flush you down the drain of self-doubt where you'll eventually ricochet into overcompensation. Sudden interest in Adele.
What to do: Yell. A LOT. Or just take whatever evidence you have and lay it on top of the pile of the other person's crap sitting outside your door to which you have changed the locks. Then go have sex with his/her best friend or relative. If you're really looking for revenge, nothing gets that person back quite like a submersing yourself in a sea of wieners. It doesn't matter if you're a guy or a girl, swimming through scrotum will really drive the point home that your ex did you wrong.
Why: The relationship has run its course. No shame in that. You hit the point where you just can't see a future. Or it could be one or both of you is panicking due to a fear of commitment (but if the other person over-uses "literally" a lot, you're right to sever ties).
What to expect: Awkward conversation where you both know it's over but you're both grasping at straws thinking you should have a better reason to end a perfectly healthy relationship.
What to do: Realize that you're both ending the relationship with a mutual understanding before things go truly sour and you start passive aggressively trying to sabotage your relationship in a less-healthy manner. Bow, shake hands, part ways, share a drink now and then.
Warning: Don't sleep together except to say goodbye, it'll just be confusing for all involved. Write down somewhere why it ended and refer to it when you're drunk at 2 A.M.
Why: One person is facing a major change and the other person is not willing to follow them on this journey. This includes moving for work, change of religion, a harsh haircut (no relationship can survive cornrows, nor should it), drastic lifestyle adjustment, tour the world on the Disc Golf Championship world circuit, whatever it may be, a major life change can create a wedge.
What to expect: Tears will flow...unless it's the Disc Golf thing then "bongs will be smoked." You will at some point question why you aren't open to new experiences. Cyber stalking will commence.
What to do: Explain this isn't what you signed up for. If the experience inspires you to start trying new things, take baby steps by starting with trying a new cereal. And turn off your computer...a lot.
Why: Somehow you didn't realize that person was of the opposite gender than the one you expected.
What to expect: A big surprise. Lots of confusion. A realization. Some anger. Experimentation. More confusion. Things won't end well, especially if the IRA is involved.
What to do: Don't be so hasty. Go have a good cry in the shower first. Then go make out with that person again and if it's just not the same, you have your answers. Leave a twenty on the nightstand and invest in some mouthwash, cowboy.
Why: Your spouse is dead but possessing Whoopi Goldberg. You realize there's no way you can go on sleeping with Whoopi Goldberg because no one can.
What to expect: A penny moving on a wall, some sassy banter, Whoopi eventually storming out.
What to do: Leave pennies around the house, ghosts can't resist moving pennies. Whilst the ghost is distracted, you're free to have a normal life. Or call an exorcist.
Whatever the reason for your breakup, have the decency to actually breakup with the person face to face and not be passive aggressive about it.