Bindi Irwin reacts to brother Robert calling her 'massive' amid her pregnancy

Robert Irwin gave viewers and hosts something to smile about on Wednesday when he unabashedly made a joke at the expense of his pregnant sister Bindi.

Robert and his mum Terri appeared live on the Australian breakfast show "Sunrise" to talk about their family series "Crikey! It's the Irwins." The conversation eventually moved to Bindi's pregnancy and the excitement about the upcoming birth of her baby.

Terri talked about the special moment when Bindi and her husband Chandler Powell announced they were expecting their first child during the family's annual crocodile research trip. She remembered they all helped pick names for the baby and they all laughed and cried. It was a memorable experience for everyone.

As for how her daughter is doing, Terri said Bindi is doing amazing. Everyone is excited to see her baby, who is due next month. She said Bindi is at that "sweet spot where you really miss being able to see your shoes."

Robert laughed and chimed in as he blurted out, "She's massive now!" His mum reprimanded him with a punch on his arm and he tried to take back what he said with a follow-up, "Like, in a good way! No, like, it's special!"

Hosts Samantha Armytage and David Koch laughed in response with the former telling Robert, "spoken like a true little brother."

"Robert you are in so much trouble with your sister," she said to which the 17-year-old replied, "I'm in so much trouble. I'm in so much trouble — don't tell her about this, please!"

Bindi, however, took no insult to her brother's TV blunder as she responded in a tweet, "Thanks Robert! Love ya!"

As for Bindi, the 22-year-old conservationist retweeted a post from Powell, where he shared his excitement about their baby's arrival. He shared a photo taken from one of their adventures together along with the caption, "Not long now until there's 3 of us going on adventures."

Bindi and Powell announced in September last year that they are expecting a baby girl. The pregnancy came after the couple tied the knot on March 25 at an intimate ceremony attended by Terri and Robert.