u/Common_Paramedic_566

They clearly had some tensions in the season because the plot wanted to show how the relationship gets real after high school but Seth always looked unhappy with summer. The chemistry just wasn't the same. He didn't seem happy like before. He always had a pout around her and not even looking at her most of the time. I mean Seth always had issue with valuing the woman he was with but this time it was different. Probably the actors broke up before this season.