Rihanna rocks the geek look in thick-rimmed glasses and baseball cap as she greets fans in Cologne

By EMILY SHERIDAN

There's not many people who can pull off the geek look and make it look good.

But then, pop star Rihanna isn't most people.

Spotted in Cologne on the Germany leg of her Diamonds world tour, the 25-year-old singer was going for a geek-meets-casual style as she left her hotel on Thursday.

Going geek: Rihanna goes for a geek-meets-casual look as she leaves her hotel in Cologne, Germany

Of course, it wouldn't be Rihanna's style not to show off a little bit of flesh - this time a flash of her flat stomach in her cropped Adidas sweatshirt.

The singer was wearing an Adidas tracksuit and Converse trainers, with chunky jewellery and a leather baseball cap.

Rihanna wore the ensemble as she headed to the Lanxess Arena for the second night of her Cologne dates.

Sporty Spice: Rihanna shows off her flat belly as she heads to her next concert

Her arrival in Germany comes after a headline-making trip to Amsterdam earlier this week.

The pro-cannabis singer posted a series of Tweets and images calling for the legalisation of marijuana.

One night, she left her hotel in the Dutch city wearing a T-shirt with a cannabis leaf on it.

She also tweeted a photo of herself smoking a roll up with the hashtag '#legaliseit'.

Busy: Rihanna is currently on her gruelling Diamonds world tour

Following her controversial stance, anti-drugs charities have hit at British fashion chain River Island, who recently collaborated on a clothing range with the singer.

Anti-drugs charities have called on River Island to drop Rihanna's range.

Lucy Dawe, of charity Skunk Sense, told the Daily Mirror: 'She should be dropped by River Island as she’s a role model to young children but clearly an appalling one.

Controversial: Rihanna in a pro-cannabis T-shirt in Amsterdam on Monday

'It is a huge double standard because if River Island were really concerned about the effects of drug use, they wouldn’t be supporting someone who is so blatantly using drugs herself.'

In response, River Island said in a statement: 'Rihanna has been contracted to design a range of adult clothes which are sold exclusively by River Island. She is not the face of River Island or its spokesperson in any way. As with all our collaborations, her views are her own.

'River Island is proud support to many charities including DrugFAM which does invaluable work supporting the families of people with addictions and will continue to do so.'