What do you give a gay man for his 40th birthday when he seems to already have everything? This guy has a loving partner, successful career and supportive parents, but when the 15-year-old son he never knew comes knocking on the door, he’s forced to reevaluate his life.

That’s the premise of Philip Middleton Williams’ award-winning new comedy, “All Together Now,” receiving its world premiere this weekend at the Willow Theatre at Sugar Sand Park in Boca Raton.

“Is it a gay play? I say no,” said longtime South Florida resident Williams. “It’s got gay characters, but when you ask if it’s a ‘gay play’ what are you talking about? Is it a coming out story? No, that’s been done to death.”

The writer did draw on personal experiences when formulating the plot. While he was living in Albuquerque, N.M. in 1999, a lesbian couple asked him to become their sperm donor. They went through the procedure three times without achieving pregnancy.

After returning to Miami two years later, Williams began to wonder “what if” the procedure had been successful and those musings provided the seed for a play years later.

“My take was not just the surprise of a 15-year-old kid showing up out of the blue—and on his 40th birthday—but the impact on him, his partner and parents and the new dynamics becoming a father might have on them,” said Williams.

Williams worked on the project intermittently for years until 2016 when Ricky J. Martinez, then artistic director of Miami’s New Theater, announced a new play reading seriesa at the company. Within a month, Williams had completed the first draft.

But, it is Joyce Sweeney’s The Playgroup LLC that will be presenting the first staged production of “All Together Now.” Williams’ play won her company’s new play competition last year and was enthusiastically programmed on the three-year-old company’s season.

“She gets my writing,” he said of Sweeney. “She understands and is very energetic about it. We have a great cast and, as I sat through the first reading, I knew they were right on the money.”

The Playgroup’s production stars Brenda Aulbach, Eytan Deray, David Ehrlich, Fran Friedman, Patrick Sheehan and Richard Weinstock with set designer Nick LoMonte and stage manager Robin Pauline rounding out the team.

In addition to Williams, the company has also successfully produced new plays by local playwrights Todd Caster, Peter Hawkins, Brian Harris, Joe Feinstein and Tom Andrew.

Even though Williams has been writing for decades and is an advisor to the William Inge Theatre Festival and member of The Dramatists Guild, he still humbly considers himself an “emerging playwright.” He particularly lauds Sweeney and her board for encouraging other emerging writers.

I’m passionate about writing,” he said. “It’s cheaper than therapy and doesn’t damage my liver.”

The Playgroup LLC presents “All Together Now” by Philip Middleton Williams on March 2, 3, 9 and 10 at 8 p.m. and March 4 and 11 at 2 p.m. at the Willow Theatre at Sugar Sand Park in Boca Raton. Tickets are $25 at WillowTheatre.org or call 561-347-3948.