AceShowbiz -

Kate Middleton's little sister Pippa Middleton is back on single saddle. The socialite reportedly has split from stockbroker boyfriend Nico Jackson after three years of dating.

Rumor has it, their relationship got strained in the past few months especially after Jackson moved to Geneva to work last summer. "Long-distance didn't work, especially with how busy Pippa was," a source told E! News. "A lot of their problems stemmed from the fact she was always busy working - as was he - and they never had time for one another."

Another source seemingly confirmed the reason of the split, telling Us Weekly, "It was mostly due to geographical issues. They were rarely together since his move [to Switzerland] and it just caused too much strain on their relationship. They still love and respect each other."

Middleton and Jackson met at a tennis match three years ago but she did not bring him to her royal enclosure at Wimbledon this year. Words were flying that they got engaged in 2013 but there never was any confirmation.

The couple was still seen together this past summer to attend some weddings. On September 18, they were spotted attending a healing arts center in London. Middleton was later seen spending time with her ex-boyfriends including banker Alex Loudon whom she dated for three years before separating in 2011 and James Matthews.