harry cressida
Prince Harry and Cressida Bonas sit together during the We Day UK event at Wembley ArenaReuters

Prince Harry and ex-girlfriend Cressida Bonas's romance appears to be back on.

The former couple, who split up in April, were spotted on a movie date in Kensington, the day after the Prince's 30th birthday.

The pair went to see the Hollywood comedy Sex Tape, starring Cameron Diaz and Jason Segal.

A source said: "They seemed very happy together when they went into the cinema. But when they knew they had been seen they decided to leave separately. It was apparent that they did not want to be photographed together. "Her taxi was heading towards Kensington Palace."

An onlooker added: "They tried hard to blend in. None of the other cinemagoers seemed to realise."

Following the covert date the prince was driven away by bodyguards while Cressida made off in a cab in the direction of Kensington Palace.

Cressida, 25, was photographed with Princess Eugenie at the Invictus Games closing ceremony on Sunday (14 September) fuelling speculation that the couple had reunited.

She had also joined Harry for his birthday party with 30 close friends joining them at Prince Charles's London home Clarence House. Harry's friend and singer Ellie Goulding performed an acoustic set.

A royal source revealed that Harry had been desperate to get back with his ex-girlfriend, who is said to have split with him due to the stress of being under the spotlight and her ambitions to focus on her career as a dancer and actor.

Prince Harry previously had an on/off seven-year relationship with lawyer Chelsey Davy before they split in 2010. The Zimbabwean-born blonde ended the relationship since she did not want a life of official duties.

Harry, the fourth in line to the throne, and aristocrat Miss Bonas met in May 2012, when they were introduced by the prince's cousin, Eugenie. But, two years later, they broke up.

It was reported earlier this month that Harry had moved on after being spotted on dates with Halo Trust employee Camilla Thurlow following a brief encounter at a club in London's Chelsea.

Harry has also shown an interest in Egyptian heiress Enayat Younes, 22, after spotting her in a Spanish nightclub.

Bookmakers Coral are now offering 4-1 betting odds that Prince Harry and Cressida will start dating again.