I get annoyed by that guy, I guess the joke is he is needlessly cruel to the son-in-law but it gets old. Don't let that put you off the show though, that is 1% of an otherwise excellent show.
When I read your post and thought "Do we have any other good Irish sitcoms outside of Father Ted and Derry Girls?", I done some research and found this Irish Independent article listing their top 12 Irish sitcoms, and I'm now laughing away at how the article itself basically shite-talks the first 6 or so shows that they chose! 🤣
As a footnote, I really need to watch "Moone Boy" some year.
The mammy. It grates after a while, but it is funny. Most of the cast are all from the same family, often playing parts that don’t match their real life relationship.