Ashley Graham Shows Off 19-Month-Old Son Isaac's Impressive Water Skills: 'Little Boy's a Swimmer'

Ashley Graham has a swimmer on her hands.

The 33-year-old model, who is currently pregnant with her second baby, shared a video Sunday of pool time with her son Isaac Menelik Giovanni, 19 months, showing the baby boy's impressive swimming skills. In the clip, Isaac jumped into the pool and swam across to Dad, Graham's husband Justin Ervin.

"Look at how good you are," Ervin, whom Graham wed in August 2010, said to Isaac, who proudly screamed to celebrate his feat.

"Little boy's a swimmer," Graham captioned the Instagram post.

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Graham opened up to PEOPLE earlier this month about expecting baby No. 2, saying that being in control "just gets thrown out the window" during pregnancy, something she learned her first go-around.

"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,' " she said. "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."

"And 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 added.

In the same conversation, the Pretty Big Deal podcast host said that while Isaac knows there's a baby on the way, he hasn't yet connected it will be his younger sibling.

"I don't think he understands the concept of being a 'big brother,'" Graham told PEOPLE. "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."