According to WoW stories, the only reason a guy would leave his girlfriend for some girl he met online is because his girlfriend is an asshole. No online interaction can lure a guy away from physical interaction, unless they met IRL. On the other hand, girls are more susceptible to this, especially in an environment with power involved such as guild or raid where the guild master or raid leader can show their "alphaness". Many stories told of and by girls who left their boyfriend when they found another guy on the internet. The pro gamer boy being good looking isn't very far fetched even though it is quite rare.