Parker thinks Eliot is the hardest lock she's ever tried to pick, because when you think you've gotten all the tumblers in place, he notices and changes the lock before you can get in.

Hardison doesn't try to pick Eliot, the man has too many rotating keys to try, but he keeps working on trying to find the pattern, because he knows somewhere in there, there's a master secret that will make it so he doesn't get shut out so easily.

Eliot watches them, deploys countermeasures as needed, and tries not to let on how close they've already come to preventing him from locking his feelings away so they can do the job they need to.