A "she was in love with me for almost her entire life and I was in love with her either but never had the courage to admit it!"-kind of jealousy.
I want to see a LOT of jealous looks toward Ollie. I wanna see Clark asking Chloe if Ollie is the one she really wants to be with. AND I want him to be unable to fully concentrate on Lois.
That's all I ask for.