Arian Foster, a running back for the Houston Texans, mocked the recent preoccupation with the ethnicity of Washington Redskins quarterback Robert Griffin III by ESPN analyst Ron Parker.

“Who is Ron Parker and wtf is blackness?” Foster tweeted yesterday. “I didn’t see the interview so I can’t make an assumption off of an article. I just hope we get past this skin sh-t one day,” he added.

This morning, Foster returned to the subject. “I’m going to work on my blackness today,” he sneered. “My mom is Mexican, so I can only optimize 50% of my blackness.”

Parker raised questions about RGIII’s ties to the black community on ESPN Thursday. “But my question, which is just a straight honest question. Is he a brother, or is he a cornball brother?” Parker said. Asked to explain, Parker added that “he’s black, he kind of does his thing, but he’s not really down with the cause, he’s not one of us . . . He’s kind of black, but he’s not really the guy you’d really want to hang out with, because he’s off to do something else.”

“I keep hearing these things,” Parker added. “We all know he has a white fiancée. There was all this talk about he’s a Republican, which, there’s no information [about that] at all. I’m just trying to dig deeper as to why he has an issue. Because we did find out with Tiger Woods, Tiger Woods was like I’ve got black skin but don’t call me black. So people got to wondering about Tiger Woods early on.”