To wronghole or be wrongholed is almost exclusively exceptionally painful for both parties and never intentional. That's not to say that to wronghole can never be intended but this definition does not deal with that. For this reason the past "too late, it's been done" tense version of the word deserves a separate entry to the standard wronghole entry.
Wrongholing most commonly happens when at least the male party is drunk, and also most commonly during doggy style coitus due to physics and biology. There are, however, risks in any position. It is the event whereby the old vaginal in out has reached such impetus that the member slips out. Usually due to alcohol consumption leading to arrogance and slow wits, the male is determined that on the return stroke re-entry shall occur perfectly and smoothly, nobody will notice and things will carry on as normal.
This is never what happens. Instead wrongholing occurs at high speed with devastatingly insufficient lubricant. It wasn't intentional, it wasn't planned, it wasn't sinister but somewhere along the ling the pecker ignored the glowing beacon of the welcoming poontang and headed straight for the rectum. Sex will stop for AT LEAST the next 5 minutes, if you're lucky, while you both roll around in the foetal position feeling pitifully sorry for yourselves.
That is to be wrongholed.