I am a deacon in my church and my wife and I have care over about 20 individuals and families. I often hear complaints from the young ladies that guys (I wont call them men) are only interested in short term relationships. They also tell me that the only men worth marrying are 10 to 20 years older than them.
Sounds to me like your pastor (or you) need to deliver a serious butt-kicking to the young men. A Biblical butt-kicking, but butt-kicking nonetheless.
If I've heard once, I've heard a million times, "I don't want my son to marry, yet......"
I sure don't hear these mothers of "boys" stating, "I sure don't want my son having sex until marriage!"
What's so awful about doing what God/nature, if you don't believe in Him, has intended you to do.
Having raised daughters, the last thing I ever wanted them to be is someone's "right of passage" to fit in with the changing times and mores.
My daughters grew up to want to be wives and mommies, not someone's live-in "girlfriend,"
Thankfully they have been that but not until two shed themselves (rather their narcissist husbands took off after another girlfriend) and have found and married men, real men not some mother's "momma's boy."