Sienna's second date with co-star Matt

The actress, 25, has now been spotted on intimate dates with two fellas this week - while her so-called beau is in town.

She enjoyed a romantic dinner date with fellow actor Matthew Rhys last night, and - on Tuesday night - she was spotted getting cosy with actor Josh Hartnett (her ex) at the West End's Paper nightclub after the Glamour awards.

The actress has grown close to Matthew, 32, while filming a love triangle drama The Best Times Of Our Lives, which includes a sexy threesome between the pair and Keira Knightley.

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Sienna Miller enjoyed a romantic dinner with actor Matthew Rhys. The two are currently filming love triangle drama 'The Best Times Of Our Lives'

Sienna Miller and Matthew Rhys filming scenes for the drama

Sienna and Matt did their best to avoid snappers last night, first trying to give them the slip after they were spotted together at a pub in London's Notting Hill.

They then headed separately to La Cantina restaurant near the capital's Tottenham Court Road at around 8pm, where they had an intimate meal.

Sienna and Matt did their best to avoid our snappers last night, first trying to give them the slip after they were spotted together at a pub in Notting Hill.

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Dinner dates: Sienna and Matthew enjoyed drinks at London's La Cantina restaurant (left) and a meal at Da Paulo restaurant (right)

A source said: "The pair looked very cosy as they sipped champagne together. At one point, Sienna gave him a small wrapped present.

"After their meal, they went to the restaurant across the road, Da Paulo, where they continued to drink until 11.30pm.

"But when they spotted photographers, they left the restaurant separately while keeping in touch with each other on their mobile phones.

"After trying to evade the paparazzi for 20 minutes, Sienna ducked into the Charlotte Street Hotel. Matthew managed to give them the slip."

Sienna was also spotted hand in hand with Matthew a week ago when the pair went out with Keira and her fella Rupert Friend.

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Sienna was spotted at the weekend walking hand-in-hand with Matthew when the pair went out with Keira and her boyfriend Rupert Friend

But the actress defended her reputation this week, when she said: "People say the most horrible things to me like 'slut' and 'slag', and it upsets me because I'm not like that.

"I've never had a one night stand in my life. I've been in a relationship more or less for the past five years, since I was 20, and sometimes people forget this.

"I know how to let it go over my head a lot, but then sometimes you do question why people are saying it. But it's not true."