In The Passion of Saint Tibilus, we are given a quick run down for why each of the three priests are on Craggy Island. Ted has the Lourdes incident which is brought up repeatedly throughout the series, Dougal is implied to have irreparably damaged a large number of lives, a good chunk of which were nuns, at Blackrock (which may have had something to do with a Sealink Ferry), but Jack’s reason for being on Craggy Island is the most obscure. The most we have to go off of is that he botched a wedding in Athlone, which he remembers fondly, given his shit-eating grin at hearing it brought up by Bishop Brennan.
Apart from that, no specifics on the extent on Jack’s actions are given, so what are your interpretations on what happened at the Athlone wedding?

Speed 4

I was at a wedding yesterday. The ring bearer was the 2 year old son of the couple getting married. The bride's parents had never been married and she has two brothers. The groom's parents had never married and he has two sisters.

It was wall to wall bastards.

Life imitates art

https://youtu.be/K2w6e2sMt-8?si=5-6fBMgy6QuQ1UxY

I haven't met Mary yet, she's away at her mothers.

https://en.wikipedia.org/wiki/Saddle_Ridge_Hoard