>Sex before marriage has absolutely nothing to do with morals, it is purely personal preference.
Your opinion, not mine.
>What if they turn out to be such a bad lay that you no longer like them? It would end in disaster.
Apparently, you value sex more than everything else about your partner. I don't. If he/she never wanted to have sex, I would even be sorta fine with that, as long as I wasn't the cause.