Mitchell Fain is probably best known for donning candy-striped tights once a year as the elf in David Sedaris’s “The Santaland Diaries.” But he eagerly took on the more serious role of Alan in Melissa James Gibson’s “This” because “it’s not an entirely comic role,” he says. “While Alan is funny, he has a sadness that I thought was really interesting and well-written, a disappointment with where he is in his life.”

Fain’s performance in Theater Wit’s production has gotten a lot of great press. And he’s a natural for the role. “The character is an educated east-coast New York Jewish gay man, so it’s relatively in my wheelhouse,” Fain says with massive understatement. The show’s being sold as a comedy, the perfect date-night outing. But it’s not really about dating, or even about infidelity. Just as the word game that opens “This” doesn’t produce a real story, so the play’s real story is not what it appears to be. That’s a red herring, while protagonist Jane’s relationship with her dead husband is at the play’s heart.

“I’m on board with you about that,” Fain tells me. “What’s clever about the play, it starts off and you think it’s going to be a quippy, Woody Allen-esque play about overeducated, self-indulgent New Yorkers and their marital infidelities and midlife crises. And what it’s really about is grief. Every character thinks every play is about them, right? In Alan’s world, he’s having his own crisis, and the death of his friend is the catalyst. The death of Roy [Jane’s husband], who’s not in the play, is a catalyst for a lot of the characters”—four of whom have been best friends since college. 

Fain does terrific work in the climactic scene of “This,” when he wordlessly comforts Jane. “One of the things that [director] Jeremy Wechsler and the cast talked about a lot was how much these people do love each other,” Fain says. “For people of a certain age, who’ve managed to have friends for a long time, there’s a level of intimacy that you can see in that last scene.”

“I have a group of friends from college myself, and one of us recently passed away—last week actually, quite a surprise. Another friend from that group was in town yesterday and came to the show. I think I under-prepared him for what it’s about. We ended up having the most beautiful discussion afterwards, about these long friendships, the many adventures, many ups, many downs… The show really resonated with him, it rang true for him.”

Fain’s last performance in “This” is March 27; he’s replaced by John Cardone for the play’s extension through April 3. (“I’ve got just the guy for you,” Fain told the Wit folks.)

“I’m going away with another Second City tour [to the Hawaiian islands, too bad], so I have to miss the extension of ‘This,’” Fain says. “But I thought Alan was such an interesting character, it was worth it to me to not have a break at all. I’m blessed and lucky, but a little exhausted.” In August, it’s time for something completely different: Fain spreads good cheer once again with the Midnight Circus in Circus in the Parks, a program he says allows you to “take your whole family to the circus, in your neighborhood, for not much money.