If online gaming has taught me anything it is the proper response at someone who is playing differently than I would.
First you should call him "n00b", because he is playing differently. Then call him "nerd", because he is playing computer game after all. Then call him "gay", because, well, frankly I don't know why, but it is crucial to call him gay. Then you should call him "13 year old kid", because only 13 year old kids play computer games. Then you should call him "virgin", which shouldn't surprise anyone since not many 13 year olds have had sex. Lastly you should find his mother and have sex with her.