How did dunny treat leola in fifth business?

During their childhood and adolescent years, Dunny has a crush on Leola and admires her very much. Although, later on, after he comes back from the war, he finds out that Leola has secretly engaged to Percy Boy Staunton. He does envy Staunton for taking Leola away but somehow feels that this is the best situation for everyone. During Leola's and Boy's destructive marriage (including Boy's infidelity and their constant arguments), Dunny comes to her rescue most of the times. Although he has no feelings for Leola, he still cares for her and even comes to Leola's aid when she tries to comit suicide