What do you do when your 8-year-old daughter asks you to dress up in a frilly costume to join her in dance class? Why, you do it, of course.

And you don't have to be a mom to jump on that invite, as Tennessee dad Thanh Tran proved.

When Tran's daughter, Adriana Cross, asked if he would participate in parent night at her ballet class since her mother, Rebecca Tran, is seven months pregnant, he gave her a little bit of flack at first.

"It's one parent with each kid," Rebecca, who took photos of the unusual class, told TODAY. "Right away when they said that, she picked her dad."

Thanh Tran (r) poses with his daughter Adriana (l) at a ballet class he participated in while wearing a tutu. Rebecca Tran

But Adriana had her caveats – she specifically wanted her ripped, bodybuilding dad to be wear a big, poufy ballerina tutu she remembered her mom wearing one year in her costume as the Black Swan.

Trending stories,celebrity news and all the best of TODAY. This site is protected by recaptcha

Her dad didn't agree right off the bat, Rebecca recalled. "She just told him he wasn't getting out of it. Right away she told him about the tutu, and he was like, 'Oh my gosh.'"

In reality, she said her husband – who is close with Adriana and regularly plays Barbie dolls with her, irons her school uniforms, and attends field trips – wouldn't have missed the opportunity to make his girl laugh for all the world.

Thanh Tran showed up for his daughter's ballet class in full tutu regalia, ready to dance, last week. Rebecca Tran

Rebecca who is due in late January, said her husband tried making up excuses at first, including, "Oh, I think the baby's supposed to be coming that day." He wasn't getting out of it.

When the time came to strut his stuff, Thanh, a health coach for competitive bodybuilders, took it to the next level, waltzing right into the building wearing the tutu.

“He had it on when he walked in the door, he wasn’t very discreet about it,” Rebecca said, and just walked right past the waiting room full of about 40 parents and children.

“Everyone automatically looked at him, and he was trying not to laugh,” she said. “I think he made a lot of people’s days; he just walked in with it right on.”

Thanh shared Rebecca's photos on Instagram afterwards with a message to other parents:

In videos Rebecca posted to her Facebook page, the muscular Thanh attempts to plié and does drills at the bar, while hamming it up for the other folks watching. Adriana, who mostly focuses ahead with a serious expression, looks back at him a few times with a repressed smile.

“That's definitely her personality; she takes her ballet classes really seriously ... she's trying really hard to do good,” said Rebecca. “It was nice to see her turn around every few moments and start cracking up.”

Adriana Cross wouldn't let her dad off the hook for her parent-child dance class this year, so her dad, Thanh Tranh, showed up ready to play the part. Rebecca Tran

While Thanh is getting hassled a little bit from clients and friends at the gym, he also relishes the time he spends parenting Adriana, and will soon be a stay-at-home dad when their son is born.

“When the baby comes, he'll be even more involved with both kids. Already that's kind of the role that we play. He packs her lunches. He's often the one that takes her to ballet classes," Rebecca said. "He's amazing when it comes to the dad role.”

Rebecca and Thanh have even discussed a daddy-daughter ballet class redux video to be shot next year, but this time Thanh will be dancing with an infant son strapped to his chest.

“I’ve already got him a few carriers. He’s going to love it, he’s looking forward to it.”