Wallflowers Don't Wilt (Rogue Scandals #1)
Raven McAllan

Ivo Daranton is bored. What he sees in a busy ballroom soon removes the boredom and replaces it with the thrill of the chase. His quarry? Serena and Arabella—Sappho-following, pinkie-linking, more than just friends.
Although they had not thought they were inclined to include a man in their lives, Ivo decides they are wrong: a man is needed, and that man is him. How he persuades them to give him and his idea a chance—or rather, how the ladies encourage him to persuade them—is as unconventional as the life they intend to lead.