Olivia was at the scene of a crime when Elliot arrived
Olivia: Hey, sorry to wake you up
Elliot: You didn't. I was helping the twins with a science project
Olivia questioned Elliot about Kathy's past pregnancies
Olivia: Elliot, did Kathy drink when she was pregnant?
Elliot: Glass of wine every now and then. Why?
Olivia told Elliot about Fetal Alcohol Syndrome that can occur even from 1 glass during a pregnancy
Elliot: I didn't know that. Guess we just got lucky
Olivia: Right, but knowing that now, if she got pregnant again, would you let her?
Elliot: If Kathy got pregnant again I'd shoot myself. Seriously, look, she gave me 4 healthy kids I trust her to make her own decision
Note: Little did Elliot know Kathy did get pregnant again in season 8, 3 seasons later (giving birth in season 9). Yet Elliot did not shoot himself...