On Wednesday, a Texas judge allowed the lawsuit by Energy Transfer Partners (NYSE: ETP) alleging breach of oral agreement by Enterprise Products Partners (NYSE: EPD) to proceed to a jury trial next month.  In a terse ruling, Dallas County District Judge Emily Tobolowsky rejected Enterprise’s motions for summary judgment and partial summary judgment, opining that they “lack merit.”

The dispute dates back to an ill-fated 2011 plan by the parties to collaborate on an oil pipeline between the glutted Cushing, Oklahoma hub and Houston-area refineries. The maybe-partners signed a joint venture agreement specifically allowing each to back out of the project, and then got busy signing up customers for the venture before Enterprise pulled the plug, citing insufficient demand.

Enterprise then partnered with Canada’s Enbridge (NYSE: ENB) to reverse the flow of their jointly-owned Seaway Pipeline along the same route, and is now working to double that route’s capacity. Energy Transfer sued the next day, claiming $1 billion in damages. It claims that Enbridge interfered with its business and that Enterprise went back on an oral commitment binding under Texas partnership law no matter what written agreements might state and regardless of common industry practices.

At first glance this looks like a nuisance suit, but a $1 billion jury verdict would certainly prove quite a nuisance to Enterprise. Energy Transfer is asserting that the marketing work carried out before Enterprise scuttled their joint venture proves a partnership existed even though neither board of directors had signed off and the written agreement specifically preserved each party’s right to back out.

This intramural Texas grudge match pits Dallas-based Energy Transfer and its Dallas lawyers against Houston-based Enterprise and its hometown legal team, with Calgary’s Enbridge cast as spoiler and co-defendant. Perhaps it’s not entirely surprising that a Dallas judge found that Team Dallas had scored enough points to permit the case to go to trial.

Texans take notions of honor and honesty as seriously as anyone, and perhaps Energy Transfer is defending those principles as much as profits. Or perhaps not. Because even as it claims that Enbridge acted illegally in breaking up its partnership with Enterprise, it’s signing up customers for an alternative pipeline route that would bring Canadian and North Dakotan crude from Illinois to Louisiana. Its partner on that project? Yup, Enbridge.

Presumably, it’s not a handshake agreement.