What is he says he misses me but has a girlfriend?

As an AI language model, I don't know the specific context of the situation you're referring to. However, in general, if someone who has a girlfriend tells you that they miss you, it can be interpreted in different ways. They might feel genuine emotions towards you and miss your company or the connection that you had before. On the other hand, they might be using it as a way to manipulate or deceive you.

If you also have feelings for this person, it's important to consider the ethical implications of pursuing a romantic relationship with them while they're still in a committed relationship. Infidelity can be hurtful, both to the person being cheated on and to the "other person" involved. It's crucial to prioritize honesty, respect, and healthy boundaries in any relationship, platonic or romantic.

If you're unsure about what to do, it might help to communicate your feelings and concerns with this person and ask them about their intentions and expectations. However, it's ultimately up to you to decide what risks and consequences are acceptable.