By the way he treats her, he treats her sweetly, always wants to be around her, and when shes not around he is still faithful to her. (talks nice about her and stands up for her)
its simple there is no difference in girl or boy!!! how a girl express her love. same way boy express his. for example/ even he looks at you with that sweet little eye. he behave like a gentle man in front of you. ask you to help you in studies. or makes you laughs everytime. AND GIVES that sweet cute smile.