Boyfriend giving another woman his number. Am I overreacting?

Celeste
My boyfriend meets a lot of people on the playstation network online. He met this new woman and is constantly playing with her added her on facebook and lies about giving her his number. I found non sexual messages from them but that is not the reason why I am mad. It's the fact that he had to lie about it. All they talk about is the game from what I see so far but I fear that he has in interest in her. Am I overreacting about this?