Booze has always flowed as freely as oil on “Dallas.” The Southfork cocktail hour was a family tradition on the original show, and J.R. and Bobby each kept lots of liquor on hand to entertain the parade of cartel members and other business associates who marched in and out of their offices each day. The imbibing continues on TNT’s “Dallas:” John Ross and Christopher routinely visit bars, and on more than one occasion, both men have come home and knocked back a stiff drink after tangling with their enemies (or each other).

To their credit, neither series shies away from depicting the downside of indulgence. J.R., Bobby and even Miss Ellie (!) all nursed hangovers at various points during the original “Dallas,” while John Ross has done the same thing on TNT’s sequel show. (Remember when he struggled to get out of bed after drinking too much with Marta del Sol the night before?) Most notably, the Ewing family also includes two alcoholics — Sue Ellen and Gary — whose struggles to stay sober never seem to end.

A handful of scenes, filmed 33 years apart, underscore this point. In “No More Mr. Nice Guy, Part 2,” one of the original “Dallas’s” fourth-season episodes, Gary comes home to Southfork to be with his family after J.R. is shot. Gary is newly sober after going on a nasty bender during “Knots Landing’s” previous season, and so when he runs into Sue Ellen in the nursery, he’s eager to commiserate with her. But as Gary soon discovers, Sue Ellen is still in denial about her drinking problem. “I am not an alcoholic,” she snaps. “I’ll admit that I take a drink on occasion to steady my nerves. But I can stop. I have stopped for months at a time.” Gary’s response: “Yeah, yeah. So did I. Thought I had it beat. But then I took a drink. And another. And pretty soon, I was on a rampage.”

The scene ends with Sue Ellen ordering Gary to “stop preaching at me” and storming out of the room. The characters don’t interact again until 33 years later, when Gary returns to Southfork during the second season of TNT’s “Dallas.” Once again, he’s recovering from a recent relapse, while Sue Ellen has two decades of sobriety under her belt. Both characters seem to be at peace with their inner demons, though, even joking about their shared disease when they run into each other at Ewing Energies. Sue Ellen spots Gary pouring himself a cup of coffee and holds out her mug, quipping that it’s “the beverage of choice for recovering alcoholics everywhere.”

Then the unthinkable happens: J.R. is shot and killed, sending the grief-stricken Sue Ellen back to the bottle. She confesses her relapse while eulogizing her ex-husband, but when Gary confronts her after the funeral and tells her it’s time to get back on the wagon, Sue Ellen lies and says she’s already stopped drinking. That night, when Sue Ellen and Gary run into each other in the Southfork kitchen, he once again offers to help her. Finally, she comes clean. “I know I need help. But I need to do it myself,” she says.

The TNT scenes demonstrate how hard it is for these two characters to break their old patterns. Sue Ellen no longer denies that she’s an alcoholic like she did in 1980, although she initially tries to cover up her relapse when Gary confronts her. (“Dallas’s” brilliant costume designer, Rachel Sage Kunin, offers a clever nod to Sue Ellen’s unending struggle by dressing Linda Gray in a black and white suit, not unlike the one she wore during her scene with Ted Shackelford 33 years earlier.) Sue Ellen continues to cover up her relapse a few episodes later when Ann questions her about her drinking and Sue Ellen denies it.

Gary has trouble breaking his old habits too. His determination to help Sue Ellen in 2013 recalls his attempt to bond with her in 1980, as well as his efforts to mentor fellow alcoholic Earl Trent during “Knots Landing’s” second season. Gary is often said to be the weakest of the Ewing brothers, but I find his concern for Sue Ellen endearing and — dare I say it? — heroic.

I hope Sue Ellen someday beats the bottle once and for all, but as far as Gary is concerned, I hope he never changes.

‘I Am Not an Alcoholic’

Yes, you are

In “No More Mr. Nice Guy, Part 2,” a fourth-season “Dallas” episode, Sue Ellen (Linda Gray) watches as Gary (Ted Shackelford) finishes playing with John Ross in the Southfork nursery.

GARY: Oh, he’s a great kid, Sue Ellen.

SUE ELLEN: I know. He’s just my whole life.

GARY: You must have really suffered when you realized you’d almost lost him.

SUE ELLEN: I don’t know what you’re talking about.

GARY: The car accident, when you’d been drinking. [Notices her stony expression] Uh, I’m sorry. I didn’t mean to dig up old ghosts.

SUE ELLEN: There are no ghosts.

GARY: I can understand why you don’t want to talk about it. I’m an alcoholic, and I know what that’s like. But you can lick it if you want to.

SUE ELLEN: Gary, I am not an alcoholic. Well, I’ll admit that I take a drink on occasion to steady my nerves. But I can stop. I have stopped for months at a time. [Smiles]

GARY: Yeah, yeah. So did I. Thought I had it beat. But then I took a drink. And another. And pretty soon, I was on a rampage. I never realized I was capable of that kind of violence.

SUE ELLEN: Gary, I want you to stop right now. Stop preaching at me. I am not an alcoholic, and I am not violent. [Leaves the room, slamming the door behind her]

‘I Know I Need Help’

Yes, you do

In “Ewings Unite!,” a second-season “Dallas” episode, Sue Ellen (Linda Gray) enters the Southfork kitchen, where Gary (Ted Shackelford) sits at the bar, working on a laptop.

GARY: [Closing the laptop] I know why you called Valene. It’s not going to work.

SUE ELLEN: I called Valene to get the two of you back together again.

GARY: You need help, Sue Ellen. And unlike my wife, I help people in trouble.

SUE ELLEN: Valene left you because she knew it was the only way to get you sober again. And she was right. She left you because she loves you. I know I need help. But I need to do it myself. You taught me that when you fall down, you get back up again. [Kisses him on the cheek] One day, she may be gone. And you don’t want to regret the loss of every moment that you could have spent with her. [She begins to walk away.]

GARY: If you ever need anything, I’m just a phone call away.

SUE ELLEN: I know that.

How do you feel about Sue Ellen and Gary’s struggles to remain sober? Share your comments below and read more “Dallas Parallels.”