Ashley Graham is bumpin' for three!
In the footage, Graham wears a black bra and high-waisted underwear from Knix as she films herself dancing in the mirror. At one point, the camera zooms into Graham's baby bump as she wiggles her belly.
"rocking the boys to sleep 😴," she captioned the clip.
Graham first announced her pregnancy in July, sharing a maternity photo taken by Ervin, 32, alongside the caption: "the past year has been full of tiny surprises, big griefs, familiar beginnings and new stories. I'm just beginning to process and celebrate what this next chapter means for us."
Ervin later confirmed the baby news on his own Instagram account, saying at the time, "Felt so nice, we had to do it twice. I'm proud of the amazing mother @ashleygraham is and will be - again!"
The couple — who are already proud parents to 20-month-old son Isaac Menelik Giovanni — revealed that they're expecting twin boys in a video on Instagram this Monday. The video showed the moment Graham and Ervin found out they were expecting, plus the ultrasound appointment when they learned they had two babies on the way.
"Are you serious? We're gonna have three boys?" a laughing Graham said in the footage, as Ervin added in disbelief, "You are kidding me!"
Graham recently opened up to PEOPLE about son Isaac soon taking on the role of a sibling, saying, "I don't think he understands the concept of being a 'big brother.' "
"He knows that there's a baby in the belly. Because I say, 'Where's the baby?' And then he points and then wants to kiss it," the Pretty Big Deal podcast host said.
While discussing her new partnership with Knix, Graham also told PEOPLE about how her body changes during pregnancy.
"I think being in control when you're pregnant, it just gets thrown out the window," she said.
RELATED VIDEO: Ashley Graham Says Body Control Goes 'Out the Window' During Pregnancy: 'I Haven't Felt the Same'
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"And I learned that the hard way when I tried to control everything when I was pregnant with Isaac and I told myself that I was going to bounce right back because I was breastfeeding and everybody told me, 'Oh, if you breastfeed you're going to lose all the weight,' " Graham added. "And I had a few honest women tell me you will never feel the same. So they were just blunt with me and sure enough, I haven't felt the same."
"Then boom. I was like, 'Well, I just got pregnant again so maybe I'll never feel the same and I don't even know what I felt like before I was pregnant with Isaac anyways,' " she said.