Are the on-off couple together again?

Justin Bieber caused a stir when he showed up at Selena Gomez‘s 21st birthday party on Saturday night.

The singer, 19, arrived at Selena’s bash at the Revolve Beach House in Malibu, California in an outrageous leopard-print sports car with his friend Jaden Smith.

And once inside Biebs reportedly indulged in a heavy PDA with his on-off girlfriend.

She was all over him,’ a source tells Hollywood Life.

They were definitely touchy-feely and shared some kisses and back rubbing.’

Justin, who’s currently on his Believe tour, managed to make an appearance at the party despite having to fly to Detroit for a gig the next day.

He even looked after Selena when she started to feel a little worse for wear, it’s claimed.

And the Come And Get It singer clearly appreciated his efforts – the pair reportedly left the bash together at around 2am.

Selena has kept quiet about her birthday party antics but thanked fans for giving her an ‘amazing birthday week‘ on Twitter.

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Anna Francis