Ashton Kutcher and Mila Kunis were spotted with her parents strolling around London on Saturday, May 18. Credit: INF Photo

Ashton Kutcher and Mila Kunis aren't just taking their relationship across the pond, they're taking it to the next level too! The lovebirds have frequently been spotted out and about in London (Kunis is currently filming Jupiter Ascending opposite Channing Tatum), but on Saturday, the pair had some extra company in tow -- Kunis' parents.

In images snapped on Saturday, May 18, the foursome were spotted taking a casual stroll through the city with Kunis' parents Mark and Elvira. Kunis, 29, wore tall black riding boots and a hood for the walk around town, and Kutcher, 35, similarly kept things low-key in a Boston baseball cap, hood and jeans. The pair held hands on occasion.

That evening, all four enjoyed Billy Elliott: The Musical at the Victoria Palace in London. The next day, however, Kutcher and his former That '70s Show costar were able to sneak in some alone time strolling through Hampstead, Northwest London, in the afternoon following lunch.

"They looked really happy," an onlooker told Us Weekly. "The weather was good and they were holding hands and swinging them as they walked. They seemed to be doing a lot of talking and joking with each other." 

Kunis previously spent the holidays with Kutcher's family in Cedar Rapids, Iowa, where the Hollywood pair dined at Red Lobster with Kutcher's relatives.

The couple have been publicly dating since last March, though rumors of the two being more than friends began to circulate after the pair locked lips at a wrap party in Los Angeles.

On Sunday evening, the foursome reunited once again, this time for dinner at Duck & Waffle, the same restaurant where Kunis and Kutcher had dined with Princess Beatrice and her boyfriend Dave Clark earlier this month.