The famous dad took to Instagram on Friday to share the cutest photo of Gigi with her mouth wide open, writing: "Happy little pup." How cute is that?
Fans were quick to gush over the tot in the comment section below his photo.
WATCH: Vogue Williams' amazing wardrobe transformation
"She's adorable, how beautiful. You've come so far! Wrote one.
"Such a gorgeous sweet looking baby," added another.
Spencer shared the photo on Instagram
Luckily for us, both Spencer and Vogue often share the most heart-melting pictures of their youngest child.
On Friday, Gigi appeared in a clip on her mum's Instagram Stories – and you just have to see her outfit!
The three-month-old was dressed in the most adorable pink fluffy dressing gown with bunny ears on her hood which made her look even sweeter. Fans can hear Vogue saying 'peek-a-boo' to Gigi as the pair look at the camera.
Gigi is so sweet!
The previous day, Vogue melted hearts by sharing a photo of her children wearing matching outfits. "Happiness is [three heart emojis]," Vogue captioned her Instagram post, which showed Theodore cuddling as they sat on the couch in coordinating PJs.
The pair were clearly ready for bed, with Gigi dressed in a cream babygrow covered with a cute koala print, while Theodore donned a matching pyjama set – both from Lil & Izzy.
And today's bunny dressing gown isn't the only time we've seen little Gigi with a rabbit ear outfit – a few days earlier, Vogue posted a snap of her baby girl in a black and white starred babygrow with big floppy ears on the hood. "Little bunny," she wrote.
We think Gigi and Theo might just be the most adorable celebrity children around!
Like this story? Sign up to our newsletter to get other stories like this delivered straight to your inbox.