Love on the Outskirts of Town by Zoe York

Matt Foster has never met a woman he couldn’t seduce into his bed. But when he meets Natasha Kingsley, there’s just one little problem—she’s not alone. Her three-year-old daughter wants a pony ride, an ice cream cone, and help to reach the highest rungs of the climbers at the park. Before he knows it, he’s spent all day with the Kingsley girls, and for the first time in forever, finds himself wanting more.
Tasha doesn’t realize who Matt is related to until he gives her his number at the end of a perfect day. Turning down his request for a second date—with both her and her daughter—is the hardest thing she’s ever done. But her history with his brother, and her firm commitment to living a drama-free life for her daughter, means she can’t flirt with, sleep with, or dream about Jake Foster’s younger brother.
Not even if he makes her daughter laugh.
Not even if he seeks her out again and shows her just how interested he is in every part of her life. Because there’s no such thing as a truly secret affair—and Tasha’s done with being anyone’s guilty pleasure.