The 21-year-old beauty was seen cheering from the audience as her hunky boyfriend put on a show for thousands of excited fans for the boys' Fit and Famous tour.
Although Jacqueline – who plays Lauren Branning in EastEnders – announced a month ago that she is expecting, there was little sign of a baby bump as she posed for photographs on the pink carpet wearing a figure-hugging white dress.
CLICK ON PHOTOS TO ENLARGE
Jacqueline Jossa strikes a pose before Dan's Osbourne's debut show
While the pretty brunette rocked an all-white autumn look, wearing a cosy retro coat and waves in her hair, her other half was seen dressed as a sailor on stage before stripping off and revealing his toned physique.
After Dan had strutted his stuff, Jacqueline was waiting for him with open arms backstage. When the show came to an end, the duo cuddled up as they were snapped looking affectionate and giggly.
Jacqueline wasn't the only familiar face in the crowd. Dan's cast-mates Georgia Kousoulou and Pascal Craymer also turned up to show their support for the newcomer.
The couple confirmed their romance back in June, and broke the news about their pregnancy in August saying in a joint statement they are "thrilled by the news".
The Only Way Is Essex star - who welcomed son Teddy in December with ex-girlfriend Megan Tomlin - added, "Becoming a father has been the most amazing thing to ever happen to me. I can't believe I'm going to be a dad again – I'm truly blessed."
Dan Osborne pictured at a promotional with The Dreamboys in August
A spokesperson for EastEnders also offered their congratulations to the mum-to-be. "Everyone at EastEnders is thrilled for Jacqueline," the rep said.