Calvin Harris has proven that he's a supportive boyfriend by showing up on Taylor Swift's perfomances for her 1989 World Tour. But the "Summer" hitmaker is taking it to another level as he adopts her cats temporarily while she's away to concerts.

"As one of the world's biggest pop stars, Taylor Swift has it pretty great, except for one thing: she often has to leave her cats, Olivia and Meredith," Teen Vogue said. "It's heartbreaking for any cat mom, but luckily, Taylor has boyfriend Calvin Harris to watch them while she's gone."

A couple of days ago, for instance, Taylor Swift shared on Instagram a photo of her cat licking her MTV trophy. She captioned the image, "Olivia Benson chewing on Olivia Benson's moon man because she is disrespectful. So glad @therealmariskahargitay took it home and away from this monster."

"But Taylor isn't home - she's on tour halfway around the world. So Calvin, who was given photo credit for the adorable kitty, was there to watch Olivia and to get Mariska her moonman," Teen Vogue added.

For those who think that Calvin Harris is a bum who just happens to wait on girlfriend Taylor Swift to finish her 1989 World Tour so they could hang out, the EDM DJ is actually one of the most in-demand musicians of his time.

In fact, according to Forbes, Calvin Harris is worth $66 million.

Of course, that pales in comparison to girlfriend Taylor Swift who's reportedly worth more than $200 million in 2015 alone.

The Sunday Express reported, per MSN, that Taylor Swift is earning $1 million a day in album sales as well as her 1989 World Tour.

"Right now, Taylor is untouchable. She is so far ahead of everyone else in the industry that she has become not only a powerhouse entertainer but also an important mover and shaker on the commercial side of the music business," LA-based media analyst Mike Raia told MSN.

As things stand, while Taylor Swift is continuing her 1989 World Tour, Calvin Harris will probably remain as the world's most-expensive cat-sitter.