Street parking issues in Houston’s ever-more-dense inner city can test the “love thy neighbor” philosophy.

But a parking dispute in the idyllic-sounding neighborhood of Magnolia Grove has escalated into an even more volatile confrontation about sexuality and religion that went viral after one neighbor installed a provocative, 16-foot long artwork designed to mimic a sign.

The conceptual piece by artist Robert Rosenberg and fabricator Melissa Eason is painted bright pink, with black and white lettering that reads: “Parking Only for Gay Conversion Therapy.” As part of the project, Rosenberg also produced bumper stickers with the tag line, “Follow me to the Blossom Gay Conversion Therapy Center, where we pray the straight away.”

Rosenberg said he conceived the banner-like artwork in an ironic tone for the openly-gay art dealer Hiram Butler, who installed it on his property at 4520 Blossom Street partly to discourage visitors to a parsonage across the street from using four parking spaces he built for his business.

“We tried reason. That didn’t work. We tried anger. That didn’t work. We put this up, and it worked,” Butler said. He said he meant it to be funny, but it’s not a joke to some.

The parsonage — a townhome valued at $783,000 — is owned by River Pointe Church, a non-denominational Christian congregation that has grown to 6,000 members since it was founded in 1996 in Sugar Land. The organization now has campuses in Richmond, Missouri City and Houston’s West End, where it merged with West End Baptist in 2015, shortly after buying the townhome around the corner on Blossom.

River Pointe co-founder and senior pastor Patrick Kelley said he and his wife Lisa live in the townhome, which is part of a row of upscale residences built in recent years on property Butler sold to a developer. The church also uses the space to host weekly Bible study meetings and a young professionals group, with other events occurring occasionally.

Kelley said he normally has about 25 visitors on Tuesdays and 10 on Wednesdays. That’s far fewer than Butler calculates, but still could account for more cars than will fit within the 12 head-in, public parking spaces on the block’s south side. According to Butler, no street parking is permitted on the block’s north side, where his property is, to allow right-of-way for emergency and police access; that’s why he built his four head-in spaces across an easement 30 years ago.

Butler and the Kelleys have exchanged more private, written complaints to each other for about a year over parking and other issues. Butler’s gallery also draws visitors who park on both sides of the street — typically once a month, on Saturdays, for its openings. And the church has rented out its townhome occasionally to Airbnb guests, although Kelley said they stopped that in April, after rowdy visitors trashed the house.

The letters sound civil. Butler, who is a devout Quaker, mentions the “give and take of urban living.”

“When you use the words mean, bullying, and entitled, you are projecting,” he wrote in one letter provided to the Chronicle. “ I admit to being persnickety. There’s a big difference. … Patrick, I was not put on this earth to quarrel with you and I do not wish to do so. One of my greatest faults and simultaneously one of my greatest failings is that I speak my mind and I don’t hesitate speaking truth to power. You are the head of the very large corporate body of a church. You have Grace. You are beyond enthusiastic. You do not like that I speak truth to power.”

Butler also shared a letter written to him from Keaton Kelley, one of the pastor’s sons, after Butler left a sharply-worded note on one of the cars of a church guest. It ends on a conciliatory note: “I am confident we will not have this misunderstanding moving forward. You have always been a fair and gracious neighbor to us, and we fully intend on being the same to you.”

Patrick Kelley did not want to comment for this report, other than to say that he still wants to be a good neighbor. “We’re very sorry we’ve inconvenienced them. We have apologized, and we continue to take every measure possible not to park in those spaces,” he said. The church is negotiating with a nearby school to use its parking lot on Bible study nights, he added.

Rosenberg, who also is a gay rights activist and a retired civil rights attorney, described himself as a “sarcastic jerk” who has always used social satire and irony in his art. He said he proposed other ideas that Butler declined, including holding gay movie nights in the gallery’s large garden when the church would be hosting Bible studies.

“For me, the message is more universal than the guy across the street,” Rosenberg said, adding that he believes the rights of gays everywhere are under attack.

Philip Carrillo, a 34-year old gay man who lives in the nearby Rice Military neighborhood, drove over to Blossom Street to see Rosenberg’s piece after a friend told him about it. He had no idea it involved a parking issue, but the conversion therapy message resonated — and made him laugh.

Carrillo, who grew up in Spring Branch, said he attended numerous conversion therapy sessions as a confused young man in his early 20s, because he was raised in a religious household and genuinely wanted to change. “I went for years hoping for some sort of eureka moment that never happened,” he said.

The artwork has been up since last month, but the dispute escalated another notch on Tuesday, when the City of Houston notified Butler he was violating signage permit laws. Rosenberg bristled, calling the notice “an abuse of power.”

Then, adding to the confusion late Wednesday, a city spokesperson said the notice was not for Rosenberg’s work but for the much smaller, discreet gallery signage on Butler’s fence. “The owner was given a notice of violation … which is considered a warning. It does not come with any fines,” said Erin Jones, a public information officer for the public works department. “It’s simply a notification to get a permit for the sign that fits Ch. 46 (the City of Houston Sign Code).”

Butler was baffled. “Why, after 30 years, would I get this?” he said.

molly.glentzer@chron.com