Thin. More likely an anti-gay couple having kids thing than any real concern over the how and who aspect. It'll be overturned. Did the lesbian couple sue for child support? Or did the state get into it on its own? If the lesbian couple didn't sue, and the state took it upon itself to ge involved, it'll definitely get overturned and the state may find a judgement against it for costs.
I think the lesbian couple is taking advantage of this man. He trusted them but should have taken legal precautions before getting involved, like a legal contract that he was only a donor and should not be held responsible for supporting the child.
This isn't and shouldn't be about lesbians. There are people who are not good people, no matter what their sexual orientation.