are same-sex classrooms unlawful?

Girl you know people don't read on here.

I think the situation that the ACLU is pinpointing is ridiculous and they should be involved. As they said, what's going on in that classroom (which isn't single sex) is based on pseudoscience and stereotypes. Having boys sit shoulder to shoulder and girls eye to eye? To me that would be the equivalent of making the autistic kids sit in a special desk with blinders on the side so that they're not distracted and can only see the whiteboard. 

In general, I think parents should have the option of whether they want their child in a single sex classroom. But there's nothing inherently wrong with single sex education and in some cases it is the best option.