5. Jeff should've put his trust in Shelli instead of Clay.
Jeff believed Shelli had full control over Clay and he made a mistake by trying to align with him. Instead, it would've been better for his game if he would have gotten closer to Shelli because he believes she clearly holds the power in the showmance relationship.
In fact, Jeff thinks the only reason Clay voted him out was because Shelli told him to, and she's running his game.