An age gap relationship is only predatory...if it's actually predatory.

If a 35 year old man with genuinely good intentions and an understanding of the responsibility he holds dates an 18 year old woman, that isn't predatory. Why? Because it isn't predatory, by definition.

If the man doesn't try to control her, doesn't stop her seeing her friends, doesn't try to mold or groom her, and treats her well with the best intentions, then there's nothing wrong with said relationship.