The confrontation between Prince Frederick and his brother Prince Joachim has reached new heights after wild claims that the younger brothers have long harbored romantic feelings for his sister-in-law, Princess Mary.

“‘Queen Margrethe’s youngest son, with clear signs of alcohol intoxication, appeared to be trying to press his lips against those of his sister-in-law,’ claimed a source in the Spanish magazine Vanitatis El Confidencial.”

“‘Maria’ brushed him off as best she could with a nonchalant smile, and Joachim’s wife Marie witnessed the uncomfortable moment.”

The publication also claims that Joachim, 53, was “deeply in love” with 50-year-old Mary, and “this was not helped by the fact that in 2007 he announced his engagement to a French woman [Marie], who bears the same name and bears a striking physical resemblance.”

Should the shocking allegations prove true, it could explain the deep rift between Marie’s husband, future King Frederick, 54, and his brother. The Danish royal family has been split after 82-year-old Margrethe stripped her youngest son Joakim’s children of their royal titles late last month.

According to insiders, the brothers’ long-standing disagreement may have stemmed from Joachim’s mistaken love.

” Fred and Joachim have not been close in recent years, and the so-called crush on Mary may well be the reason,” an insider told Woman’s Day.

” It would also explain why Mary and Marie have never been close despite being sisters-in-law.”

Vanitatis El Confidencial claims that the rift between Fred and Joachim’s families became so noticeable that Margreta “called them to order” and “launched a campaign designed to show that there are no problems between the two women.”

According to Woman’s Day insiders, Margrethe tried to keep the feud between her sons quiet for years, but things eventually came to a head.

It is also believed that Fred’s fury at his brother was one of the reasons his mother publicly stripped her youngest son’s children of their titles as princes and princesses.

“Joachim is furious at the way it all happened and blames it on Fred’s ego and his ability to convince their mother,” the source says.

“Joachim has not publicly denied his crush on Mary but has been forced to do so privately. He claims that he and his family have been left to fend for themselves through petty family squabbles and gossip.”