Every time you bring up this his name, your girlfriend asks way too many questions about who your boy is dating. She wants to know the name of the woman she saw him with last, when they met, how serious it is, and if you think it will last.
It would be cool if she asked you once and kept the conversation moving to a different topic. However, if a conversation about your dude's dating situation is the only way you can hold her attention for more than ten minutes, you should be wary.
Perhaps she is just genuinely curious. Or maybe she's trying to see how she can fit into the picture.