It looks like there might be a reason why Pippa Middleton has been so unlucky in the love department these past few years. A new report suggests her sister Kate Middleton and Queen Elizabeth are on a quest to keep the British socialite single--for their own benefit, of course.

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According to Celebrity Dirty Laundry on Wednesday, Pippa was spotted heading to the gym by herself on Valentine's Day, prompting speculation that she is once again single. The party-planning enthusiast broke things off with her long-term boyfriend Nico Jackson late last year and was rumored to be dating her ex-boyfriend James Matthews, but unfortunately it looks like they weren't able to reignite a spark between them.

Now, there are whispers saying that no one seems to be happier seeing Pippa single than the Duchess herself, as she apparently doesn't want her sister bringing any unnecessary attention to the royal family.

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Blogger Amanda Austin wrote, "Kate Middleton and Queen Elizabeth balk at any prospective gentlemen she tries to date, because they don't think they are suitable to be dating one of the future Queen's family members. The last thing they need is Pippa bringing more unnecessary scandal to the Royals."

She added, "As long as Pippa's sister Kate Middleton is in line to be the future Queen Of England, Pippa is going to have to either settle for one of the less than interesting gentlemen that the Royals pick for her. Or she could go against their wishes and date whomever she wants--but she can also plan on being 'cut off' if she does."

Tell us, Enstars readers, what do you think? Is Kate Middleton the reason why her sister Pippa is still single? Drop us a line in the comments section below.