Lady Gaga, Justin Bieber & Ellen DeGeneres: What You Need to Know About the …

Saint Laurent creative designer Heidi Slimane hosted a star-studded fashion show at the Palladium for a guest list that included Lady Gaga, Justin Bieber, Ellen DeGeneres, Portia De Rossi, Zac Efron, Sylvester Stallone, Lily Collins, Emma Roberts, Demi …