He's the Married At First Sight groom known for his love of a good night on the town.

And on Saturday, Jason Engler raised eyebrows when he was spotted attending former MAFS star Davina Rankin's 30th birthday and engagement celebration.

Davina famously shocked Australia in 2018 when she embarked on Married At First Sight's first-ever cheating scandal.

While it's unclear how Jason, 35, and Davina know each other, the pair appeared to be comfortable with each other posing for a series of friendly photos. 

In one photo, Jason is seen smiling as he placed his arm around the mother-of-one while she playfully shimmied for the six second boomerang.

Jason opted not to wear the commitment ring given to him by wife, Alana Lister, on the Channel 9 dating show, suggesting the couple may have split since filming the show in September.

The outing was a joint celebration to celebrate Davina's 30th birthday, and her engagement to her longtime boyfriend Jaxon Manuel. 

The reality TV villain announced the joyful news to her 360,000 Instagram followers on her 30th birthday on Friday. 

Flashing her engagement ring to the camera, the influencer wrote: 'I guess 30 isn’t looking too bad after all.' 

In the image, Jaxon had his arms around the 30-year-old. He planted a kiss on her cheek as she flashed her ring.

Jason married 'hot school teacher' Alana Lister back in September on MAFS. 

Meanwhile, Davina was 'married' to construction worker Ryan Gallagher on the show in 2018. 

Married At First Sight continues Monday at 7.30pm on Nine