It was Lois saying "Here we go..." in the episode Ultra Woman. That cute little scene in which they were researching something, Lois is looking over Clark's shoulder and kissing his shaving nicks.
Mirage, the shaving nicks happened in Ultra Woman - if you remember, that's the episode where the Newtrich sisters shot him with a red Kryptonite ray and his powers were transferred to Lois. So... a non-superpowered Clark equals someone not used to shaving with normal razors, which equals... shaving nicks. Ouch!