Harry Styles and Zoe Kravitz "had an amazing summer together".

The 31-year-old singer and Zoe, 36, have been dating over recent months, and "things are only getting more serious between them".

A source told The Sun newspaper: "Harry and Zoe have a real connection -- this is love.

"It's a real honeymoon period and they're barely apart.

"Zoe has to get back to work on a film so she's coming to London and will be staying with Harry while she's here.

"They've had an amazing summer together and things are only getting more serious between them."

The celebrity duo have been spotted together in various parts of Europe over recent months, and Zoe's dad, rock star dad Lenny, approves of their burgeoning romance.

The insider explained: "Zoe thinks Harry is cool without trying and that's a very attractive quality in ­Hollywood, when most people are too busy trying to desperately break through or stay relevant.

"He treats everyone the same, whether they're famous or not and she's found that refreshing.

"Lenny is like that and growing up with such a famous dad, that ethos was instilled in Zoe -- to be kind, to never be a diva."

In September, a source revealed that Lenny gave Harry his seal of approval.

The 61-year-old star "enjoyed meeting Harry" and he "appreciated Harry's sense of humor".

The insider told People: "Friends of Lenny say he is very protective of Zoe, but it really seemed like he enjoyed meeting Harry. From what people could tell, he thought Harry was polite, down to earth and genuinely interested in getting to know the family.

"Lenny has always wanted Zoe to be with someone who respects her, and it looked like he felt Harry does. They were laughing a lot at lunch, and it came across that Lenny appreciated Harry's sense of humor. He likes when someone can keep things light."

Lenny is actually "all for" the new romance.

The insider added: "Lenny's not the type to rave, but the vibe was that he was comfortable with Harry and for Lenny, that says a lot.

"At the end of the day, what matters most to him is seeing Zoe with someone who really appreciates her. He's not the type to meddle, and from the way friends saw it, if Harry keeps treating Zoe this way, Lenny's all for it."