Anyone who has lost their virginity before the age of 18 should not be proud, they are a clear example of their parents failure, a failure that includes the child drinking and smoking before the legal age limit, and/or trying illegal drugs,. If you try to defend your parent’s failure, then you are bound to repeat their failure as parents when you have kids of your own.
One who's parent's have failed to be decent, must accept their parents failure, and try to break out of the vicious circle, otherwise as stated above, they are bound to repeat the failure themselves, and so we get ever closer to realising the world of "Idiocrasy" (funny movie, but one that points where we are headed, watch it if you haven't and then you'll understand what I'm refereeing too.)
I define a 'decent' parent as one who has instilled good values and discipline into the child, to the point the child goes through the troublesome teen years (usually 13-18) with out having tried alcohol and cigarettes, or having literally fucked around like little hookers. Once the child is of voting age (usually 18), then they are free to do what they like as at that stage the parents have done what they can to ensure their child is a decent member of society. Of course there's more to good parenting than just preventing the child from trying tobacco, alcohol, or sex before the legal age, but these are the most common bad things a child can do and since it pertains to the thread it's self this is why I’ve only pointed out these instances.
My 2 cents.