Bokong Jeniffer Aniston Dipegang Gerald Butler

They've been constantly hamming it up for the cameras as they travel around Europe promoting their latest film.

But if Gerard Butler and Jennifer Aniston still want to convince us that they're nothing more than just good friends, then they really need to try a bit harder.

Because while grabbing your leading lady's bottom for the red carpet flashbulbs is one thing, doing it when you think no one's looking is really quite another.

Behind you... Gerard Butler thinks he's secretly grabbing Jennifer Aniston's bottom as they pose for pictures on a boat on the River Seine in Paris last weekend

The pair were snapped posing for pictures aboard a yacht on the River Seine in Paris on Saturday, as they explored the French capital while on their promotional tour for their new release The Bounty Hunter.

As Jennifer, 41, warmly put her arm round her co-star's waist as they were snapped with a lucky fan, Gerard placed his hand on her bottom.

And clearly this wasn't just a cheeky pat either, as Gerard, 40, appeared to really get a good handful of her pert derriere - little realising he was being snapped from behind at the same time.

Hands where we can see them, please! Jennifer and Gerard pose up in Madrid but he seems rather bored of the whole premiere routine - and who can blame him?

Rock chick: Jennifer shows off her long tanned legs in a short embellished black dress and high strappy heels

Not that Jennifer seemed to be complaining either, although we can only guess what was said between them afterwards.

The pair has taken some time out from their hectic promotional schedule to take a dinner cruise up the river to see the sights of Paris, including the Eiffel Tower and the Place de la Concorde.

And a source close to the actors told People that they stayed very close, 'hugging and touching each other', as they dined on green salad and grilled chicken and lobster, washed down with champagne.

Sassy senorita: Jennifer put her rhythm to the test as she joined dancers on stage at the Corral de la Moreria club in Madrid

Ole! The actress got right into the spirit of things

They have been at the centre of rumours about their relationship ever since they began filming together, but they have consistently denied they are dating.

From Paris they travelled to Germany where they attended the Berlin premiere of The Bounty Hunter, which translated as Der Kautons-Cop.

The film is an action comedy which tells the story of struggling bounty hunter Milo, played by Butler, who finds out that his next assignment is his bail-jumping wife Nicole, played by Jennifer.

Good times: Jennifer looked like she'd had a ball as she finally called it a night

Yesterday, they were whisked off to Spain for a photocall in Madrid for the film, which translates as Exposados in Spanish.

Then last night, it was time for the glitz and glamour of the red carpet again as they attended the premiere in the Spanish capital.

Jennifer looked stunning in a strapless rock chick-esque black dress and killer strappy heels, while Gerard looked his usual handsome self in a suit and tie.

After the premiere, the pair were then treated to a visit to a local flamenco club where they enjoyed a night of traditional Spanish dancing.