Battle Of The behinds! Kim Kardashian Bumps into bootylicious Serena Williams

Her second pregnancy has so far led to little change in her wardrobe.

And Kim Kardashian chose another revealing look on Friday before bumping into her old friend Serena Williams who couldn't resist touching the star's growing belly. 

The bootylicious ladies embraced on the street outside Harrods and Kim placed her hands on her hips as the World Number One tennis player rubbed her baby bump.