text: why do guys whistle? i like a guy but i never know if he likes me. we are not too close. when there are just me and him, he always whistles.  i am just too shy to make eye contact with him coz i don't know what he thinks. so why he whistles when i am there? should i say hi to him next time? guys whistle because they can.  but to answer your real question, you should say hi to him and ask him about his day and make small talk like that.  then let things flow from there.