The two stars of the upcoming Waterfront Playhouse production of “Mothers and Sons” in Key West started on stage at a very young age.

“Mothers and Sons,” by part-time Key West resident Terrence McNally, is the story of Katherine, a Dallas mother who makes a surprise visit to the New York apartment of her dead son’s ex-lover Cal (Matt McGrath). By this time, Cal has married another man, Will (Trey Gerrald) and they have a 6-year-old son of their own, Bud.

Widowed herself and virtually alone, Katherine longs desperately for a family that no longer exists. Haunted by her son’s ghost and weighed down by anger, Katherine finds true hope and promise in the evolving definition of family and in Bud, the grandson she never had.

“Mothers and Sons” runs Jan. 26 through Feb. 13. Tickets are $25 to $50 and can obtained at www.waterfrontplayhouse.org.

McGrath’s acting career began at age 5 when he played Trouble in the New York State Opera production of “Madam Butterfly.” By age 8, he had created the role of the newsboy, John, in the Broadway production of “Working.”

His Broadway credits continued as he played the emcee in “Cabaret” (with Brooke Shields) and Hedwig in “Hedwig and the Angry Inch.” He just completed two successful off-Broadway runs, starring in “The Legend of Georgia McBride” and “Steve.”

You can also see McGrath on the ABC comedy “Modern Family,” in which he has a continuing role as Simon, Mitchell and Cameron’s arch-nemesis.

Gerrald also started acting in elementary school, which spurred him to attend a performing arts high school in Greenville, S.C., and major in musical theater in college.

While McGrath was performing in “Cabaret” in New York, Gerrald was doing the same thing in Hilton Head, S.C. After college, he garnered recurring roles in TV series including “Orange is the New Black on Netflix,” “Next Caller” on NBC and “Deadbeat” on Hulu. He’s in the 2016 movie “Wiener-Dog” with Danny Devito and Ellen Burstyn.

This is McGrath’s first time performing in Key West and Gerrald’s third; he just bought a house in Bahama Village.

Gerrald’s first visit to Key West was to see his husband (then fiance) David Perlman perform in “A Dog Story” at the Waterfront. On a lark, he auditioned for “Next Fall” (also at the Waterfront). He got the part, so he and Perlman returned the following year for stage work.

“Mothers and Sons” premiered on Broadway in 2014 and was nominated for a Tony Award for best play Tony Award.

Rounding out the Key West cast are Joy Hawkins as Katherine and Jake Ferguson as Bud. Hawkins is artistic director for the Red Barn Theater and she also acts. Ferguson is a newcomer, just age 8. The director is Murphy Davis.

“The sheer sense of community is so strong here,” Gerrald said. “Even though I haven’t been here in months, I can’t go to the grocery store without people welcoming me back to town and asking me what play I’m going to be in next.”

“You can read about the creative history of Key West from Hemmingway to Tennessee Williams,” McGrath said. ““But you really don’t get a sense of how deep it runs until you’re actually here.”