HAH, ah thanks, you made me laugh and laugh.
It can cause lasting physical, emotional, and spiritual harm.
At the last DC I ever will attend, a loved-up married Bethelite espoused the virtue of virtue, and came out with this; 'We could talk all afternoon about the dangers of fornication', and I started making a list, and realised that yes, we could talk about it all afternoon. For example they could make up for the sex ed. classes they forced us to miss because they were afraid we'd get horny reading about IUDs. Or they could tell me in detail exactly what is wrong with the kind of sex when nobody accidentally falls pregnant or gives somebody a STD, ie, when it is safe, which is as simple as, well actually I don't know; I wasn't allowed to do sex ed. Or they could talk about the emotional harm that they inflict upon the poor kids who step outside the boundaries of what they consider perfect, and the spiritual harm they cause when they pretend that as long as you underline the answers in the watchtower and clock up average hours every month, you've got all the god you'll need.
I just can't find the words for how much I despise what they did to my heart and soul.