In The Bible As a Human Witness to Divine Revelation, I read Jennifer Pfenniger's essay, "Speaking or Smouldering Lips in Song of Songs 7:10 (Eng. 9)?"
The translation of Song 7:9 that Pfenniger initially offers (the RV) reads as follows. I have inserted in parentheses the important Hebrew words that Pfenniger will discuss.
"And thy mouth (chiketh) like the best wine,
"That goeth down smoothly for my beloved,
"Gliding through (dovev) the lips of those that are asleep."
There are other ways to understand this verse. The KJV, for example, translates "dovev" as "causing to speak," the idea being that wine loosens the lips of those who are sleeping.
Pfenniger goes into the scholarly ideas about how to translate "chiketh" and "dovev," along with the bases that scholars have offered for their translations. She also discusses the scholarly debates about who is speaking in Song 7:9---the man or the woman.
After offering her arguments, Pfenniger settles on the following translation of the verse. Again, I've put the Hebrew words she discusses in parentheses.
"Narrator: He waits for you (chiketh) like good wine: Coming for love in rightness.
"Woman: He causes to pine (dovev) the lips of sleepers."
The point here, for Pfenniger, is that "the woman protagonist rises to protest the languishment that waiting for love 'like new wine' has produced."
What about the sleepers in the verse? Pfenniger states that the point here is that "just as the woman pines for love's consummation, so does the man, leaving the lips of both sleepless, restless, and unfulfilled." Pfenniger cites Song 5:2a, which affirms that the woman is sleeping, even as her heart is awake, as well as other passages in Song 7, which talk about the breath and kisses. The idea, for Pfenniger, is that the woman is impatient for love to be awakened---which may mean that she's still waiting to see her beloved (my guess).
I didn't really want to get into the details of all of the arguments in this post, but it's interesting to see an alternative understanding of the text.