Whether you’re lost in a foreign country or waiting for test results, being with someone you love can slow your heartbeat. As I saw when P.O.S and his mom visited The Current, this also applies to interviews. I walk into the lobby and find Grace first, sitting with her hands folded. Her shoulders loosen as soon as she spots her son. “Mommy!” he yips, bringing her into a hug. Just like that, we’re off to an honest and often hilarious conversation about their love for music and each other.

P.O.S, whose real name is Stef Alexander, and his mother Grace Zimmerman are pals. It’s obvious from the moment they sit down on the couch; eyes glinting, they sip coffee and catch up on everyday goings-on.

They’ve been pals for a long time. With Alexander’s saxophonist dad out of the picture, the pair spent most nights together when P.O.S was young. After work, Alexander says, “She'd come home all tired and make me some food, and we would just camp on the couch and watch TV in that American, raised-by-TV way.”

They’ve also got a somewhat professional relationship; Zimmerman has run merch operations for Doomtree – aka P.O.S and six other Minneapolis rappers and/or producers – since the crew started selling it. Her basement is Tuesdays with Lazerbeak legend, having housed merch from pins to tank tops to Doomtree: Every Single Day, the coffee table book the crew released in 2014. “The worst pre-order was that book,” Zimmerman says, and Alexander laughs. “They landed in America from being manufactured overseas – they came over on a boat,” he explains. “And they just showed up at my mom's house with pallets on pallets on pallets, like we were a factory.” Alexander’s son Jake and stepdad Doug came over to help get them inside, and Doomtree spent an afternoon signing each copy.

Way beyond business, though, Zimmerman and Alexander have had each other’s back. Early in her son’s career, Zimmerman provided room, board, and support while he focused on “getting good quick.” For his part, Alexander seems to provide a more emotional support; he knows how to make his mom laugh, as he proves over and over.

As I suspected, Alexander isn’t the only family member who’s into music. “I love to sing,” Zimmerman says, and Alexander insists her voice is “better than she will say.” She accepts the compliment. "My husband and I met because we were both out singing all the time," she says. They'd see each other from across the karaoke bar, until eventually they started duetting on songs like "You Got Me Babe" and "You Don't Bring Me Flowers.”

Their family does not stop at duets. "When we get together, we tend to sing," Zimmerman says. "Our wedding was kind of a musical." As soon as she said “I do,” she picked up the mic for “At Last,” wearing the white dress and all. “I sang; the guy that married them sang; Dessa sang,” Alexander says. "It was maybe the best wedding I've ever seen."

These days, Zimmerman and her husband visit nursing homes to sing with residents who may need a dash of joy. They used to own a karaoke business (yes, Doomtree karaoke exists), and the gear still comes in handy. We start talking about what's appropriate to perform at their nursing home gigs. No bummer songs and no heavy cuss words, Zimmerman declares. "But I sang 'Creep' there!"

Zimmerman doesn’t play any instruments, but she grins when she remembers watching her son practice the drums. They didn’t have access to a kit, so – why not? – he used his pants. She’s in full-fledged embarrassing story mode now, laughing at the memory: “He used to wear these hard, baggy pants with the clunky shoes with a Barbie doll head. I still got that, by the way." Alexander steps in to describe the shoes: low-top, steel-toe Doc Martens with guitar strings instead of laces. Zimmerman just goes back to imitating his drumming.

There's one more key part to the story: honorary tattoos. Early on, Zimmerman would not have called herself a fan. But Alexander started getting tattooed when he was 14, and one day, he came home with the name “Grace” on the back of his hand. Why there? “I think I got this tattoo so she couldn't complain about my hand tattoos,” Alexander says, and he bursts out laughing. “She had to like it, because it was for her.” After her retirement five years ago, Zimmerman started racking up her own body art, getting the No Kings symbol, the “P.O.S” autograph, and a few other small tattoos on her arms.

Alexander is on tour over Mother's Day, but it’s not a problem for his mom. “We don’t have Mother’s Day traditions,” Alexander says. But they don’t really need them, since they have dinner or meet up once a week. With one exception: “When those pre-orders go up,” Alexander says, “I maybe come over a bit less because I don't want to help pack stuff up.” His mom looks up at him. “I didn’t know that!” she protests, laughing, and shrugs at me. Alexander’s face is all mischief, but he does note, “A lot of times, if you get a package from Doomtree, I put it in the mailbox. I helped!”

We wrap up, and Zimmerman says, "It occurred to me that it was just me and you for a really long time. Even when other people were around." Alexander nods. "Couple boyfriends, couple cool people around. But for most of my life, it was just me and Ma."

Happy Mother's Day to everyone who celebrates it. P.O.S performs at Rock the Garden on June 16.