father and son

I have two daughters and one son. My husband clearly favors the son. He coaches his sports, which is huge because my son is so athletic. Our girls are in dance, but since that is not a sport, not only does he not help, but he doesn't even ask about it or attend their recitals. He's all about our son. The girls seem to be getting the message that in order to get Dad's attention, they need to be male. When we are at home my husband and son are usually in front of the tv together watching some sort of ball game. The favortism is so obvious yet when I mention it to him, he says I'm making something out of nothing.

sounds like your husband sees his son as a "mini-me."
the issue is not sports but his ability to feel empathy. I'd be pretty direct with him about how he could lose his daughters if he does not show them the needed attention. he needs to be prodded to take them to breakfast one on one or to show up at their events, even if (heaven forbid) it means missing a ball game.
also, the girls need coaching from you about how to be assertive with males. i'm hoping you can stay on top of their feelings and give them the gift of empathy they do not recieve from their father.
watch dr. les' videos on narcissism.