Las Vegas can find any reason to throw a party. Earlier this month, it was a fragrance launch. The champagne glasses clinked, the partygoers mingled and the guest of honor, a 100-milliliter bottle, sat back and took it all in. Ermenegildo Zegna inside the Forum Shops at Caesars hosted the launch party for Zegna Intenso, the new men’s fragrance now available. With notes of green mandarin, Italian lemon, Iris and pink peppercorns, the scent is a cocktail of surprises. Zegna calls it virile, contemporary and sophisticated. That alone is worth a toast.