I lived with my husband for 1 1/2 years before we got married and truthfully I don't think it helped/hurt our relationship in any way. Because people grow and change. We're both completely different then we were then. We got older, our views/opinions on things changed. In some areas we've grown closer & in others we've grown apart. And this would've happened if we'd lived together or not.

As for my own children I would let them because I guess it would allow them to see if the guy was a complete jerk before getting married. But there are no guarantees with anything in life.