Katy Perry and Orlando Bloom are getting "more serious" about each other.

Katy Perry

Katy Perry

The couple have been dating for some time now but have been acting more "low-key lately", prompting speculation things are getting serious between them.

A source told PEOPLE magazine: "They have been more low-key lately and seem more private about their relationships. They act like they are more serious.

"Orlando and Katy are spending the weekend at his Malibu house. They went to Malibu Soho House on Saturday. They sat on the patio and looked very happy."

Meanwhile, Katy and Orlando were "really sweet with each other" when they dined together in West Hollywood earlier this month.

An insider shared of the couple's date at Sunset Hotel's Tower Bar in California: "They were super low-key and having a good time. They were really sweet with each other."

And the 'Dark Horse' hitmaker and the 'Pirates of the Caribbean' actor are getting on so well that Orlando has chosen to introduce her to his son Flynn, five, who he has with ex-wife Miranda Kerr.

An insider said: "Katy and Orlando are doing really well. They have been hanging out a lot over the past two months. They are a very chill pair ... They both communicate great and laugh when they are around each other.

"Katy has met Flynn, and they get along wonderful. She thinks he is so cute and such a well behaved kid! Katy would [also] like kids one day, and she is vocal about that."