If you read the article all the way through, you discover toward the bottom the acknowledgment by the sponsoring group that the group which did the study develops sex education materials for the schools and that some of the materials it “studied” were developed by the group itself. So, yes, I would say there’s a bias. What bothers me is why Fox would publish such a press report where it is clearly an unreliable result.
The necessary implication is that there is "Republican" "sex", "Democrat" (ugh) "sex", etc.
Not a good source I'd say.