Here's an interesting topic. I've been reminded recently how the cultural elite thinks that Southerners are sexual perverts. Just a couple days ago I watched an episode of Louis C.K. where a redneck pulled a gun on Louis to get him to have sex with his sister. Just last week I watched Midnight Cowboy again which suggested that the Southern protagonist was sexually abused by his grandmother. That reminded me of the "purdy mouth" scene in Deliverance. More recently, Texan Killer Joe, played by Matthew McConaughey, obsesses on a young girl. And so on and so on.
I looked for data on the question. I had a difficult time finding anything, but the GSS has asked participants if their religious leader has ever made sexual advances, and this is certainly sexually deviant (sample = 1,758). The percent for Americans in the non-South is 2.3 percent, while it's 2.6 percent in the South; they are not significantly different. Plus, the rate in the South might actually be lower if you take into account the fact that the non-South is less religious and thus has a smaller share of its people that are at risk of clergy abuse.
UPDATE: I equalized the situation by only looking at people who attend at least nearly every week. The non-South percentage rises to 4.2%, while the South's rises to 3.7% (N = 531). Still no significant difference.
UPDATE UPDATE: These low numbers contradict the picture presented in Grapes of Wrath of ministers having sex with members every time they get to feelin' the Spirit.