Orlando Bloom and Katy Perry have keys to one another's homes.

Orlando Bloom

Orlando Bloom

The 'Lord of the Rings' actor - who has a four-year-old son, Flynn, with ex-wife Miranda Kerr - is smitten with the 'E.T.' singer and the pair have now taken their relationship to another level and have been "practically living together" since going on vacation to Hawaii last month.

A source said: "They've barely been apart for weeks, so Orlando figured he should officially give Katy a key to his apartment so she can come over whenever.

"She was thrilled and offered him one to her place on the other side of LA too.

"They spend most nights at his place and practically live together but the holiday cemented things between them. Now she's happier than ever."

The couple - who have been dating since January - didn't even try to hide their affection for one another during their sunshine break.

A source said: "They had an amazing time. It was such a relaxed, fun holiday full of hiking, swimming and eating - they couldn't keep their hands off each other.

"You could tell they've fallen hard. They didn't seem to mind who saw them."

The break was particularly significant for Katy, who fled to Hawaii when her marriage to Russell Brand hit the rocks in 2010.

The source told heat magazine: "Katy loves Hawaii and always rents the same place.

"It was the house she hid out in when things went wrong with Russell - she was there when he sent his 'I want a divorce' text.

"It meant a lot to be able to make new memories there."