Megan Mullally is back on this week's 'Parks and Recreation,' threatening to ruin Ron's relationship with the lovely and amazing Diane -- is this one problem Leslie can't solve?

When Ron is invited to a woodworking awards ceremony (nominated for a chair he made), Tammy shows up to rain on his parade, and while Leslie frets and tries to protect Ron from Tammy's salacious attempts at unnerving him, it's Leslie that Diane is more worried about. Over the years, Leslie has learned everything about Ron -- so much so that she knows how to give him an appropriate birthday or Christmas present, she knows how to console him, and she knows all the intimate details of his torrid romantic history. Rather than create a superficial, petty, and stereotypical conflict between Diane and Tammy, "Ron and Diane" goes for the less obvious by having Diane feel threatened by how much better Leslie knows Ron, and how Diane feels like she'll never be able to measure up or achieve that same level of intimacy.

It's an interesting concept and one that's ultimately relatable -- it's easy to feel threatened by a significant other's friend, especially when that person is a member of the opposite sex. It may not be that we feel romantically threatened, but that we feel platonically threatened because a relationship is a work in progress, and it can take years to really get to know someone -- why not feel jealous that someone already knows them as well as you wish you could? Friendships are special, and as Leslie and Ron discuss, their relationship is strictly one of friendship, and neither is attracted to the other. What Diane has to realize is that she has something Leslie and Ron will never -- and don't want -- to have, and that's special in its own right.

Plus, we get to see Ron really fight to keep Diane, and it's always a delight to see him so motivated and inspired by something other than scotch whiskey and woodworking, which leads him to introduce a part of himself to her that no one ever gets to see -- not even Leslie: Duke Silver! And beyond that, we get to watch Amy Poehler and Megan Mullally engage in some seriously hysterical physical comedy as they chase after each other in the name of Ron's future.

Meanwhile, April, Andy, Tom, and Donna have spent so much time making Jerry the butt of their jokes that they've even invested money in his daily failures, and they use that money every year around Christmas to go out for a fancy meal. But their constant dissing of Jerry based on his silly fumbles has led them to ignore the genuine good of Jerry, who invited them all to his Christmas party, and when they decide to invite him out for their "Jerry Dinner," they discover that while they were leaving Jerry out of their fun, they were leaving themselves out of a really special treat.

Oh, and by the way, we finally get to meet Jerry's wife Gail, who turns out to be incredibly attractive and sweet, just like his daughter Millie (and their other two equally attractive daughters). Christie Brinkley guest stars as Gail, and she's a real delight to watch as she charms the recently-depressed Chris and almost causes Ben to have a heart attack at the mere site of her. It's always great to see how consistently surprised Jerry's co-workers and friends are by him because they always underestimate just how great of a person he can be beneath his clumsiness and bumbling behavior -- as if that somehow negates his goodness and makes him incapable of nabbing a smoking hot wife and popping out three beautiful daughters. It's become a running joke, but one that never wears out its welcome.