Mamma mia! What's a son to do? Gianni, a weary, down-at-the-heel aristocrat, shares a cramped Rome apartment with his bossy mother. She's 93, and doesn't move around as easily as she used to. But she's a regular Trevi Fountain of opinions, reminiscences, directives and complaints. She expects Gianni to see to her desires molto presto, though he's no spring chicken.

Their budget is another complicating factor. Gianni's charm persuades the local shopkeepers to let him buy groceries and wine on credit. Alfonso, the landlord, is not so flexible, but he is creative. He offers to forgive Gianni's debt in exchange for his baby-sitting Alfonso's own elderly mother. It's the traditional late summer holiday and everyone wants to get out of town. Alfonso doesn't crave a long car trip with his young girlfriend by his side and Ma in the back seat. Besides, wouldn't Gianni's mother enjoy the company?

No, she wouldn't. Imposing, set in her ways, and disinclined to share her TV set, mother prefers living among memories of her former affluence. Exposing her reduced circumstances to a stranger would be humiliating, and admitting that it would be embarrassing is doubly humiliating. It takes a miracle of diplomacy but Gianni persuades her to go along with the arrangement. Unexpected guests keep arriving as Gianni is bribed, blackmailed and bullied to take in more elderly ladies.

The film's writer/star/director is Gianni Di Gregorio (primarily known as a screenwriter of the searing Mafia thriller "Gomorrah"). He does a wonderful simmer of vexation as the harried host. Di Gregorio's air of sozzled exasperation is a cocktail of pained dignity and abashed ineptitude. His genteel daily glass of wine multiplies along with his stress, and he finds welcome distraction in cooking continually for his demanding harem.

Gianni's long-suffering patience is stretched to agonizing lengths as he juggles his visitors' conflicting personalities, dietary restrictions and medication schedules. He's a man used to putting a face of unflappable insouciance on trying circumstances, but serving as waiter/nurse/errand boy at this ad-hoc elderhostel could prove too much even for him. The story deftly avoids pathos and sentimentality, but it percolates with compassion, ending on an unexpected but charming upbeat amid new friendships.

"Mid-August Lunch" is a sweet-spirited gem, warmly comic while showing the hassles of caring for aging relatives more honestly than 10 family sagas from Hollywood.