In all fairness, I think you're sending mixed signals here.

Always arriving during their last set sure sounds like you are interested in him. Turn the situation around for a moment. If you were the one in the band and there was someone that had a brief fling with you, and that someone was constantly stopping by just as you were finishing up, wouldn't you think they were still interested?

Networking or no networking - don't go to that bar at all on nights when his band is playing. Its as simple as that.

Good luck.