What is he has a girlfriend should i stop talking to him?

As an AI language model, I cannot provide personal advice, but I can provide some information on the situation. If someone you are talking to has a girlfriend, it is important to respect their relationship and their partner's feelings. Continuing to talk to them may make their partner feel uncomfortable or even hurt. It is up to you to decide whether you want to continue talking to them or not, but it is important to consider the potential consequences of your actions. If you are interested in them romantically, it may be best to step away from the situation and find someone who is single and available for a relationship.