After she questioned where she ranked in the list, he replied: “I was going chronologically. You’re right between Koothrappali’s father and Omar, the one-eyed Sparkletts guy.”
However, despite Bernadette (Melissa Rauch) and Wil both making their first appearances in season three, episode five in the episode called The Creepy Candy Coating Corollary, Sheldon didn’t meet Bernadette until five episodes later.
Sheldon briefly became friends with Wil at a Mystic Warlords Of Ka’a tournament – which took place at the same time Bernadette was meeting Howard on their first ever blind date.
Therefore, the pair made amends before becoming on and off nemesis’ once again long before he met Bernadette.
source: express.co.uk