Did Dale Secretly Love Peggy?
Did Peggy reject Dale at some point? What else would explain his irrational hatred for her and his constant need to remind everyone (i.e. Hank) that he has the superior wife?
Is a past relationship ever hinted at? They would seem to be perfect for each other. On the rare occasions they work together or hang out without Hank, they have an amazing rapport.
Of course, a relationship was out of the question as long as status-conscious Peggy knew she could do better, and let's not hint (although it would have been delicious) that Bobby might have been Dale's son. Bobby's resemblance to Cotton proves their relationship, and Dale's to Bug rules out the possibility that Cotton fathered Dale.