Article continues below advertisementOK! has pictures of the hottest celebrities out and about this month. Scroll Down To See what your fave celebs have been up to this spring!Article continues below advertisementSource: Anna SokolInside Nicky Hilton's ( above with mom Kathy Hilton) Theo Grace launch party in Bel Air, featured in the Season 15 finale of The Real Housewives of Beverly Hills which aired on April 16.