Do they really want to have sex that bad, thats why they get married? I never understood that.Not everybody of course. Everybody and their own reasons are different. But what I've observed it seems to play a big role. Plus, not to mention that when you are not allowed to have sex, it turns into masturbation that is also forbidden. You will feel even more bad, sexually frustrated and guilty which then increases the change of bad mate choice. Masturbation is yet another smart control tactic.
There was one couple in my congregation who got married at the 17 year mark and then later after they got 2 kids, divorced because the woman cheated. Reason? I don't know, but would guess growing separate and "Jehovah" is not really a reason to keep marriage together. Another bullshit lie to keep witnesses marrying witnesses.