“The Real O’Neals” is a situation comedy that looks at what happens when the foundation of the ideal family starts to crumble or as MTV’s “The Real World” put it over a decade ago: What happens when people stop being polite and start being real? The answer, in the case of this ABC show, is a sweet and funny portrait of an imperfect family.

Eileen O’Neal (Martha Plimpton) is active in her Catholic church and smoothly runs her household. Her children, Jimmy (Matt Shively), Kenny (Noah Galvin) and Shannon (Bebe Wood), each excel in various ways. Her husband Pat (Jay Ferguson) is a respected police officer in their Chicago community. They are the picture-perfect family until 16-year-old Kenny comes out of the closet and Pat confesses to the kids that he and Eileen are getting a divorce. Mining the comedy from this premise without depending on cliches is tricky and the show succeeds thanks to writing that stresses tender family bonds and performances that feel authentic.

Plimpton is great as Eileen, a “Catholic gangster” as Kenny calls her in one episode, who finds ways to reconcile the reality of her family life with her traditional beliefs without abandoning either. Plimpton plays her with a dry wit, landing every punch line. Most importantly, she makes Eileen likable in all her fussy, political incorrectness.

The show charmingly portrays parent/child dynamics. In one episode, Pat is determined to help Shannon deal with the practicalities of getting her first period after she asks him not to tell Eileen who, his daughter says, will just keep telling her not to get pregnant. His efforts are funny, if slightly predictable — there is a scene where he goes with Shannon to buy feminine hygiene products, but it ends with him offering her something from the heart: A “tool kit,” presented in a literal tool box, that includes everything she might need.

Similarly, the sibling relationships are portrayed as supportive and kind and real. Jimmy looks out for Kenny, albeit in misguided and humorous ways, and their banter feels genuine. The scenes where Kenny talks to Jimmy about how to navigate his dating life are often laugh out loud funny.

But it is Eileen’s relationship with Kenny that is the heart of the show and their mother-son bond is touching as Eileen struggles with Kenny being gay. Kenny, narrating the action, offers one assessment: Eileen has started to refer to his sexuality as “the situation” which is “step two of the 94 steps of accepting your gay child.”

The show also deals with contemporary issues — as the first out gay student at his Catholic high school, Kenny becomes a reluctant spokesperson for the LGBTQ community — but keeps the tone light. Fantasy sequences express Kenny’s vivid imagination, adding to the comedy, and Galvin nicely balances Kenny’s innocence with the character’s emerging sense of empowerment.

“The Real O’Neals” is about accepting life in all its messy realities. In a social media world of carefully curated perfect moments, it’s a welcome reminder of the value of imperfection.

“The Real O’Neals” is on Tuesdays at 8:30 p.m. EDT on ABC.

— Melissa Crawley is the author of “Mr. Sorkin Goes to Washington: Shaping the President on Television’s ‘The West Wing.’” She has a Ph.D. in media studies and is a member of the Television Critics Association. To comment on Stay Tuned, email her at staytuned@outlook.com or follow her on Twitter at @MelissaCrawley.