The picturesque Park Slope brownstone of J.Crew president and creative director Jenna Lyons and her estranged husband, Vincent Mazeau, is on the market for $3.75 million through Sotheby’s. We revealed last week Lyons is in a messy split with Mazeau and has fallen for another woman, jewelry exec Courtney Crangi. Some wondered who’d wind up with the townhouse on Garfield Place, featured in Elle Decor. But the home, bought for $1.3 million in 2004, will now be sold.