Pippa Middleton
Pippa MiddletonReuters

Pippa Middleton's future brother-in-law Spencer Matthews grabbed media attention on Friday by stripping down to his underwear for a promotional event to kick off London Fashion Week.

To "showcase the near-future of fashion retail", Lyst, an online fashion site, used Matthews and other models as mannequins to promote advanced retail technology. While he showed no qualms in stripping down to his underwear, it remains to be seen how his future relatives, Duchess of Cambridge Kate Middleton and her in-laws view this publicity stunt.

Back in August it was reported that Kate wasn't too happy with sister Pippa's engagement to James Matthews, solely because it would result in her being related to Spencer. This is even said to have caused a strain between Pippa and Kate, who have shared a comfortable relationship in the past.

"[Kate] is horrified about Spencer being Pippa's brother-in-law," a source told Life & Style at the time. "Spencer has slept his way around London and left a lengthy trail of angry women in his wake," a different insider revealed. "Kate's concerned. The last thing she wants is for William's family to turn against her because of Spencer's actions."

Spencer is a former star of Made In Chelsea and the British version of ABC's hit dating reality show The Bachelor. He is known for his womanising ways and he once told a girlfriend on the show that it was hard to respect her when she allowed him to cheat. He also revealed intimate details of his sex life in a 2014 tell-all memoir titled Confessions Of A Chelsea Boy. In it, he claimed to have slept with at least 1,000 women, and describes his experience engaging in a sixsome with some "nifty Canadian girls."

In Spencer's defense, he has been keeping himself away from the limelight till recently, probably due to his brother's upcoming wedding to Pippa.