Drooling in your sleep is not sexy. Drooling is not cute or romantic or meaningful.
But a lot of us do it.
And if you’re going to fall in love with someone, you have got to be down with the fact that the person you’re falling love with is a human being like anyone else, and that they drool and poop and have bad hair days and sometimes throw up and maybe pick their nose.
That’s just what people are like.
If you reduce them to a hackneyed concept like ‘they look younger asleep,’ you are losing so much potential for characterization and meaningful emotional connection with your readers.