You may possibly know someone like Ted. He’s the best friend who graduated high school with you 15 years ago but who never moved on. Who takes up semipermanent residence on your couch with a bottle, a bong, or the remote. Who always has a great idea that gets you in trouble with your girlfriend. No need to tell him to get stuffed. In “Ted,” he already is.

Writer-director Seth MacFarlane’s debut feature film is a crass, foul-mouthed, mostly hilarious, surprisingly sentimental bromance about a grown boy named John and his teddy bear. John, warm and wonderfully dim, is played by Mark Wahlberg. The teddy bear, Ted, is voiced by MacFarlane with the punchy Boston accent of a guy who hangs out at the packie all day.

Years ago, in his lonely youth, John wished his Christmas present would come to life, and through the miracle of angels and digital effects, it did. Now John is 35 and trying to be a grown-up, with a girlfriend, Lori (Mila Kunis), and a job. Ted, with his taste for weed, politically incorrect jokes, and hookers, is all that’s holding him back.

If you’re a fan of MacFarlane’s animated TV empire — the long-running “The Family Guy” and its various iterations — you’ll know to expect cheerfully smutty gags and smart pop-culture throwaways. “Ted” just increases the verbal filth. It’s remarkably inoffensive for all that, although anyone who takes a child to this just because there’s a teddy bear on the poster should have their head examined.

The movie works not because the gross-out jokes are funny (MacFarlane bats about 2 out of 3) but because the two central relationships, between John and Kunis’s tough, tender Lori and between John and Ted, feel real — or real enough. Ted really is that friend you can’t outgrow even when you want to, who shares your taste for bad ’80s movies , and who believes adulthood can be avoided if you just don’t show up for it.