Chris Pratt and Katherine Schwarzenegger are ''very serious'' about each other.

The 'Guardians of the Galaxy' star and the 28-year-old author are a ''great fit'' and pals wouldn't be surprised to see the pair getting engaged sometime soon.

A source told People magazine: ''They're such a great fit together. 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.''

And Katherine is also getting on well with Chris' son five-year-old son Jack.

An insider said recently: ''They are spending every day together and Katherine has met Jack several times. They seem to be getting more serious ... It's still very new between Chris and Katherine but the picnic was not their first date. They have been on multiple low key dates and have been talking consistently for the last two months or so. They both really like each other. Chris is smitten by Katherine and is super happy about how it's going so far.''

This marks Chris' first romance since splitting with Anna in August last year, whom he was married to for eight years.

At the time, he released a statement, which read: ''Anna and I are sad to announce we are legally separating. We tried hard for a long time, and we're really disappointed. Our son has two parents who love him very much and for his sake we want to keep this situation as private as possible moving forward. We still have love for each other, will always cherish our time together and continue to have the deepest respect for one another.''