The tattoo was done at Boston Barber & Tattoo, which, as Vice pointed out, has had its fair share of experience with Patriots tattoos.
Although, is it really fandom when someone gets another person's face tattooed on their ass? It seems a little more like an insult.
But (haha, pun intended) judging from the fact that the guy who got the ink was wearing a Brady jersey and hat while getting it done, we can safely assume that yes, he's probably a fan. A big fan. A HUGE FAN. Hopefully one day he gets to show off his tattoo to Tom Brady himself. I'm sure he'll be so pleased.