I got an A2 in my leaving cert many years ago so i suppose I'm fluent

Kiss my ass - pog ma thon (pronounced h-own)
fuck off- foc il leat (pronounced latt)

There are different dialects through the country. Different words are used for some things in each region.
Irish Dictionary Online - Irish English Dictionary

I always new the word for penis as been budgeen. I never saw it in the written form as their would be no need for it for Leaving Cert But in other regions it's known as slat. In my translation a slat is a rod