I can't remember the exact line but I always liked the moment when someone said to Lois that she must be the dumbest woman on the planet for not realising that Clark and Superman were one and the same. It acknowledged something that it was impossible not to think

I think that's in the second season, by the villain with all the letters as his name, and yes, meta acknowledgment. Which reminds me that someone - I think Yahtzee - once wrote a great story about Joyce (Summers) called "Being Lois Lane". Pity the loved ones of superheroes saddled by the narrative in not realizing the obvious!

(In Supreme Power, JMS goes meta too by letting Mark suggest to the goverment people he could have a normal job under another identity, disguising himself by wearing glasses. They just give him a look and say "no".)