14 year old boy bringing beer to a party, getting a 14 year old girl drunk, and then "having sex" (actually, rape since she is not of right mind) with her - illegal, on MANY accounts for MANY reasons.
I see you didn't really get the point. Let's say the kids have sex already using condom. When there is a party and the kids' judgement gets fogged by alcohol, they even more likely to have sex and even unprotected, because what's the harm? They already have sex, so it is not a big step for them.
So it doesn't need to be a rape. But to further the scenario, if your daughter has a reputation already that she can be have easily, at the same party getting raped can happen much easier...
Oh, Imagination...
Since I was that 14 year old, I assure you that it did me zero harm.
According to kids nowadays oral sex isn't even considered real sex. Love and affection go away but herpes is for forever.
By the way you are arguing from the kids' POV and pretty much anyone over 20 would agree that the later they start the better. So you must be young, if not, I hope your daughter starts having sex at 13, after all you want her to be experienced for an everlasting marriage.
Anyhow this horse has been beaten to death....