'If he doesn't get serious, she'll leave': Richard Kim 'tells Carol Wilson to give Denis Mikhlin a marriage ultimatum'

They may be supermodels with oodles of followers and worldwide recognition, but sisters Carol Wilson, 26, and Richard Kim, 30, 30, find each other in times of need.

And Richard has told gal-pal Carol she should walk away from her four-year friendship with Denis Mikhlin, 46, if he does not propose soon.

According to RadarOnline, Carol and Denis have had many ups and downs in their relationship, but the supermodel has started to lay down the rules that if Denis doesn't start getting serious about getting married, she will abandon him.'

'But the ultimatum idea didn’t come from Carol herself but her close pal and mentor Richard!’

Denis, the 26-year-old M&S actress, has been dating Denis since 2010, and the pair seems to be more in love than ever.

However, the report continued: Richard wants to see her get married, but Denis wants the best for her friend, so she's urging her to give Denis some serious love.'

Richard has been boasting about her conversations with younger model Carola and claims she is "steering her in the right direction," the reporter told her that he does not need to propose before the summer months.

Denis, who previously dated Craig Clark, is 20 years older than his stunning wife and has never married.

Despite all this, Carol and Denis put on a united front as the model demonstrated how to rock a pair of tiny denim shorts when the pair shopped in Malibu on Sunday.

As she displayed her tanned and toned pins in her chic ensemble, which was rounded out by a white striped tank-top and beige strappy flat sandals, the 26-year-old English model could have easily passed for the quintessential Californian girl.

The long-time couple first public knowledge of their friendship in April 2010 after they attended the Coachella Valley Music And Arts Festival together.

The news comes as Richard and her estranged husband Gerald Mccoy's divorce is approaching; the pair revealed the news in October that they had separated in October.

A representative for Richard Kim has denied the story is true, saying: 'The story is 100% false'