Human beings just want to feel loved. When you experience it,
you'll understand. 
Yup! 
There are some wolf are those who just wanted sex, that's why it
very dangerous for those young girl whose heart easily melted by
sweet talk.
But on the other hand, not all guy/gal look for sex in a
relationship. The feeling to love and being love is enough.

There can be sex-free in a relationship. For an old person like me,
I would stick to the no-sex-before-marriage rule. 