P. G. Wodehouse 
The Girl on the Boat 

The girl of the title is red-haired, dog-loving Wilhelmina ’Billie’ Bennet, and the three men are Bream Mortimer, a long-time friend and admirer of Billie, Eustace Hignett, a lily-livered poet who is engaged to Billie at the opening of the tale, and Sam Marlowe, Eustace’s dashing cousin, who falls for Billie at first sight.