The guy who your girlfriend is jealous of because you spend more time with him than you do with her. He is one of your most loyal friends and will not hesitate to back you up in any situation.
This is somewhat like platonic cross-sex friendships. For singles, platonic friendships can both be more valuable and more fraught with stress. It may exist, but they require both parties making their intentions clear from the get go. Women should be able to recognize when a male friend wants to be more than friends. Below are examples of when a male is showing that he wants to be more than friends.
Your male friend asks what you cooked for dinner and then asks when you will cook for him.
Your male friend calls you every night and talks about nothing much.
Your male friend suddenly becomes critical of your looks.