The *NSYNC star welcomed his children with husband Michael Turchin via surrogate on Oct. 13
Lance Bass and husband Michael Turchin
Credit: Lance Bass/instagram. Inset: Getty

Lance Bass is in "heaven" with his two bouncing babies! 

The *NSYNC star, 42, shared a trio of adorable photos to his Instagram on Thursday, showing his newborn twins Violet Betty and Alexander James as they reclined in their onesies and cooed.

"The kids have hit the giggling phase now," Bass wrote in the caption. "It's heaven!"

The former boyband star welcomed his children with husband Michael Turchin via surrogate in October of this year.

Turchin, 34, also shared an adorable baby portrait on Thursday to his own Instagram, showing the babies donning fashionable getups in shades of pink and blue.

Earlier this month, the famous couple spoke to PEOPLE about how fatherhood has been treating them thus far, saying it's been "easier" than initially expected.

"It's actually been better than expected," Bass said in last week's issue of PEOPLE. "It's been a lot easier than we thought. We're just lucky — and knocking on wood right now that this doesn't change."

He added, "They've been so well-behaved. They don't make too much noise. They cry when they need to get changed and fed."

Turchin also said he's "surprised" by just how smooth their transition into parenthood has been since welcoming the twins on Oct. 13.

"I thought once the kids came, I'd just be constantly a nervous wreck," he said. "And it was literally the most opposite. I think because we were just so calm and not in crazy new parent mode, when they came, we were just going with the flow. I think that rubs off on the kids, I think they really pick up on that. They're just such relaxed, fun, good kids so far."

RELATED VIDEO: See Inside Lance Bass and Michael Turchin's Twins' 'Eclectic, Imaginative and Peaceful' Nursery

Despite being twins, Turchin noted that Violet and Alexander are already showing off "two very different personalities," much like he and his own twin sister did as babies.

"[Violet] is way more strong-willed and way more active, and way more opinionated and vocal. And then little Alexander is such a sweet, docile little boy," he said. "Right now they're just starting the phase where they're starting to smile back at you. It's the best thing in the world, when you see that smile on their little faces. It's like, 'Oh God, I never want to leave this house ever again.' "

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To prepare for their babies' arrival, Bass and Turchin, who married in 2014, designed an "eclectic, imaginative and peaceful" nursery with buybuyBaby and Decorist designer Max Humphrey in their Los Angeles home.

Among the special touches they included was a Nursery Works Compass Rocker, which Bass said he likes to settle into at the end of the day for his favorite part so far of raising his kids.

"When they're sleeping on your chest," he said, "that's the best feeling in the world."