During the second season of 'Rescue Me', we met more siblings for Tommy Gavin, both in and outside the nuclear family unit. He was shocked to find he had a half-brother who was a priest, and for a while Tommy thought Father Mickey's sister was also his sister as well. But as it turned out, Mariel wasn't related to him after all.
They might have acted upon their mutual reaction to each other, if it hadn't been for Tommy's renewed "fidelity" to his wife.
Also, his long-lost prodigal sister Margaret returned to the fold near the end of the season (but only because she thought Daddy Dearest was coming into a massive fortune). Add to all of these siblings Tommy's brother Johnny, who's a police detective and one thing is certain - the nut didn't fall from the tree. Just like Tommy, his Dad Mike Gavin couldn't keep it in his pants; probably busting his nut with more women we don't even know about yet.
So I'm thinking it's not too incendiary an idea that Tommy Gavin might have yet another half-brother, one who - with Tommy - could be considered twin sons of different mothers.
This would be Mike McNeil, a detective with the NYPD, as seen in the TV show 'The Job'.
Although he carried the last name of his mother, Mike McNeil was probably named after his biological father, Mike Gavin. I'm still working my way through the boxed set for the complete series of 'The Job', but so far as I can tell, his parents won't be showing up.
And even if they did, it doesn't negate this theory. Mrs. McNeil might have been having an affair with Mike Gavin.
It's theories like this that make Toobworld kin to the conecpt of the Wold Newton Universe as first proposed by writer Philip Jose Farmer.
For more information... information... information about the Wold Newton Universe, check out the listed link for Win Scott Eckert's website. And keep an eye out for his new book on the subject, MYTHS FOR THE MODERN AGE: PHILIP JOSÉ FARMER’S WOLD NEWTON UNIVERSE, which is available for pre-order from Amazon.