Awww! I was so hoping he'd blurt it out before Lois could start to pretend. But she got in there first with her 'interview' and then he began to suspect.
But what the heck is going on. I got the impression he was going to tell her, even though he came to the conclusion she didn't know, and then ... BAM ... he has to break up with her on his birthday!!!
Nooooo.
(And what did really happen in that hospital bed????)