John Legend (and his adorable kids!) star in a new Pampers commercial celebrating dads, which airs in full on Super Bowl Sunday

John Legend — with the help of his 8-month-old son Miles Theodore and daughter Luna Simone, 2½ — is celebrating hands-on dads everywhere this Super Bowl Sunday.

The EGOT-winning musician is helping to launch Pampers‘ “Love the Change” campaign with a new commercial, which will be released in full on Sunday, and can be seen in a teaser clip singing his “Stinky Booty Song” as he changes Miles’ diaper. After seeing what’s in the diaper, Legend makes a face, cuts his crooning short and turns to Luna to say, “I’m going to need some backup on this one.”

In response, Luna adorably throws the baby wipes his way — but they don’t make it far.

While the little girl might not be much help in the video, Legend, 40, tells PEOPLE exclusively that she has embraced the role of being a big sister to Miles in real life.

“She’s really loving to him,” he says. “I would say she’s jealous of him in the sense that whenever one of us is holding him, then she’s like, ‘Hold me too! Hold me too!’ But she never takes it out on him. She has never been mean to him in any way. She’s super loving and tender with him, and I think she takes pride in being a big sister. But she doesn’t want to share the attention that much still.”

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Legend says he and wife Chrissy Teigen have been singing the “Stinky Booty Song,” which he created, to Luna ever since she was just 1 or 2 months old. “She still loves the song even though she’s potty-trained,” he says. “We’re using it on Miles now.”

When it comes to being on diaper duty, Legend tells PEOPLE that he and the model, cookbook author and Lip Sync Battle host, 33, have split it pretty evenly with their kids.

“It’s just whoever is able to do it at that time,” he says. “It has never been a thing where it’s like, ‘You have to do it or I have to do it.’ It’s like, ‘Okay, I have him right now and his diaper needs changing, I smell it, I’m going to change him.’ I’ve always been like that, and never felt any hesitancy to do it.”

“I had never changed a diaper before Luna, but I learned quickly,” Legend explains. “It’s not hard — just do it. I think us having dogs has made it easier to deal with the whole poop of it all. Once you get used to poop, you’re not too squeamish about anything.”

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To Legend, taking care of their dogs has proved to be just as much work as the babies — if not more so when it comes to cleaning up after them.

“The dogs are worse!” he says with a laugh. “They [poop] on the carpet when they’re young and they do all kinds of terrible things. They’re worse than kids, as far as I’m concerned. Once you get past that, changing diapers is nothing.”

Legend tells PEOPLE that Luna makes him “laugh all the time” since she has a lot of her mom’s personality, and that she recently had him cracking up over a phrase she used to comfort her grandmother Vilailuck Teigen.

“She said to my mother-in-law when something went wrong, ‘It’s okay, it’s not the end of the world,’ ” he recalls. “I’m like, ‘How does she know what [that] means already?’ I don’t even know where she got that from. I know every parent says they have no idea where their kids are getting all of these phrases from, but they get them.”

He says he and Luna like to do all kinds of things to bond, including swimming and dancing together.

“Music is a big part of our relationship,” he says. “We have this record player in the dining room at our house and sometimes we’ll just have daddy-daughter time in the dining room — close the doors and dance to music on the record player. That’s her favorite thing to do to bond with me.”

Miles, on the other hand, is just about to crawl “any second now.”

“It hasn’t happened yet, but he’s sitting up,” Legend says. “He was [born] early so he’s a little late when it comes to every milestone. He’s still catching up on weight and all those things because he was born several weeks early. But he’s doing so well, and he’s just a sweet baby. He’s so calm and loving and smiles so much. He’s the perfect baby.”

When it comes to having two little ones running around the house pretty soon, the “All of Me” singer says to bring it on.

“I like when they are in control of themselves and can talk back to you and you know what they want,” he says. “It’ll be interesting seeing two of them doing all of that at the same time. I prefer Luna talking, communicating, understanding how to take care of herself to some extent.”

“You still have to watch her, but she understands what danger means and how to be safe and things like that so you don’t have to watch every second of every move she makes,” he continues, adding with a laugh, “So I like that phase more than I like the helpless phase. I’ll be looking forward to Miles when he gets a little older.”

Legend’s new Pampers ad will be released during the Super Bowl since millions of families will be tuning in to watch together, but this year’s big game has been particularly controversial as thousands of people have asked Pepsi Halftime Show headliners Maroon 5 (along with Travis Scott and Big Boi) to back out of the performance in support of former 49ers quarterback Colin Kaepernick, who started the take-a-knee movement to protest police brutality.

Legend, who has long been outspoken about his support for the take-a-knee movement, recognizes that it’s a complicated situation for not only the NFL, but also the acts performing during halftime.

“I always support the take-a-knee movement, but I also never said that I was boycotting the NFL or that other artists should boycott the NFL,” he says. “I think it has been a complicated journey for everybody because I think on one hand, there are a lot of players who are still taking a knee as we speak and we’re seeing that happen every Sunday on the field and those players are still playing and that’s great, but it is disappointing to see that Colin’s not playing since he was the original face of that movement and that particular action.”

“It’s disappointing to see that he still hasn’t gotten a job in the NFL, and I hope he still does,” Legend continues. “I’m rooting for him, and I’m also rooting for the underlying issue, which is saying, ‘We need to do better in our criminal justice system that still too often has a separate and unequal system for people of color.’ No one protest or one quarterback is going to solve that. Even the NFL can only do so much to make a dent in that issue. But I think it’s important that he brought that issue up to America, as other activists have done, and it’s important that we keep having a conversation about it.”