Since "Mahone" is a surname, pogue Mahone means "kiss Mahone". It is clearly a PUN on pó mo thóin. Tóin is not a naughtly word per se, but I suppose kissing someone's bottom is naughty. There is area of Rann na Feirste (in County Donegal, Ireland) called "Tóin an Bhaile" and I hardly think the residents would translate that as "the arse of the town"!

It seems to me that some of you would also be interested in looking up the "Pedantic Crack" thread.