Quip puzzles are not a favorite puzzle type of mine, but when I finally read the entire quip today, I literally LOLed. As it happened, I got the last part of the quip first, and couldn't imagine for the life of me how OFEM could possibly be right. Funny.
In fill, I very much enjoyed LADIDA (1D: Pretentious) and coming off that, DITSY (17A: Like a dingbat). Another good pairing was LUSH (10A: Sot) and SIN (12D: Sloth, for one). Also good were NOCOMMENT (18A: Stonewaller's response), MANUP (6D: "Stop being such a wuss!"), and KFC (56D: Company with a bucket list?). And I smiled at the word "liquidy" in 48A: Still liquidy (UNSET).
In the unknown/whaa?/something we've learned department is OPS (18A: Saturn's wife). And here's an odd coincidence, after we finished the Wednesday puzzle yesterday, I went back into the archive and started a Thursday puzzle from April 19, 2012, and in it was the clue "He once wrote 'Last but not least, avoid clichés like the plague," and today we have 45D: Wordsmith who wrote "Last but not least, avoid clichés like the plague" (SAFIRE). Since it was a different constructor, we think it might be a favorite quote of Shortz'.
In the end, the quip was excellent, and the fill was above par. A satisfying Thursday.
Favorite clue/answer pair: 44A: Trap (KISSER). So inappropriate.