The pair, who was first spotted together during a picnic on Father's Day earlier this summer, have been getting serious recently
Credit: Jason Merritt/Getty; Imeh Akpanudosen/Getty

Chris Pratt and Katherine Schwarzenegger might be walking down the aisle sooner than expected.

The pair, who were first spotted together during a picnic on Father’s Day earlier this summer, have been getting serious recently.

“They’re such a great fit together,” a source tells PEOPLE. “It’s only been a few months but Chris and Katherine are both very serious about the relationship and their friends wouldn’t be surprised if they got engaged sooner rather than later. Katherine has spent time with Chris’ family and they all love her too. She fits in really well with them and vice versa.”

Pratt, 39, and Schwarzenegger, 28, first met through her mom Maria Shriver and have often been spotted out spending time with each other’s families. Schwarzenegger — who is Shriver and ex Arnold Schwarzenegger’s eldest daughter — has also bonded with Pratt’s 6-year-old son Jack. The three have been seen out on happy ice cream and lunch outings in the last few months.

WATCH: Going Strong! Chris Pratt and Katherine Schwarzenegger Do Dinner with Her Family After Church Date

Last weekend, the two were photographed enjoying themselves at the Round Pond Estate winery in Napa, California, where they sipped on the local wine with friends — including Pratt’s brother, Cully.

“What a weekend! We had the distinct pleasure of hosting Mr. Chris Pratt and Miss Katherine Schwarzenegger and friends this past Saturday,” the winery wrote on Instagram, adding that the two were “every bit as warm and hilarious as you’d think!”

This marks Pratt’s first relationship since his split from Anna Faris, 41, in August 2017 after eight years of marriage.