Couples counseling?! Well, that's not what I expected.
OK, new theory (because I think my last one was completely wrong) - What if Happy and Toby start openly dating and Walter, seeing how happy they are, becomes very jealous. Since Walter isn't good at identifying his emotions, he just starts taking it out on Toby and when it starts causing problems at work, they are sent to counseling to work it out. When they figure out that he is jealous because he wishes he and Paige could have a relationship too, Toby encourages him to end his no fraternization policy.