Just like tasting ice cream flavors, sampling sex with a new guy is what being young and single is all about.When marriage and children are deferred well past the teens or early twenties, one doesn't expect people to live celibate lives.
Still, sex is an extremely powerful drive. A libertarian attitude toward sex is compatible with a recognition that the power of the sex drive warrants respect.
Spending the night with someone and then deciding if a relationship is possible strikes me as a dubious lifestyle.
I might be wrong, of course. A strong indicator will be whether the hookup generation has stable marriages and a sustainable birthrate.