What if a guy shows he likes you but hides it by going out with other girls?

If he is "hiding" it then he has his own reasons for not approaching you. Normally if a guy does like someone though he will not go around dating other girls as that could hinder his relationship with you so maybe he is not really interested as you may think. It is best not to wait around for him as it seems he is busy with others and may not be boyfriend material or one to commit.