If sand volleyball players are mostly naked and gymnasts in leotards are half naked then grandma and her knee length skirt is one quarter naked. Correct?
Especially when they preach about how women are supposed to dress, and how their "immodesty" (which usually means not wearing a long dress or skirt) makes men struggle with their thought life.
So either the pastor does not mind having a naughty thought life, or his preaching is very wrong.