"Deathtrap" may have debuted more than 30 years ago, but one Utah mother was "disgusted and infuriated" by a surprise gay kiss in the plot after seeing the Ira Levin play at a local theater.

The unnamed woman wrote an angry letter complaining to Chris Lino, the managing director of the Pioneer Theatre Company on the University of Utah campus in Salt Lake City, after she and her son attended a recent performance of "Deathtrap." She apparently thought Lino's playbill should have provided a content advisory about the same-sex kiss.

"I am normally calm, mild-mannered, and don’t get upset, but last night, at the close of the first act of 'Deathtrap,' I was infuriated with the explicit, homosexual display on stage because I had brought my teenage son to see the seemingly innocuous play," she wrote in the letter, reposted to Facebook by Pioneer. "I realize that, unfortunately, you feel you must appeal to an insignificant minority of patrons by offering 'edgy' material. I regret that you feel that way. I have wasted many tickets the last two years by choosing NOT to attend plays that were offensive and vulgar."

The woman wrote that she left at intermission and demanded a refund.

Her letter continued thus:

I am appalled that you could not have simply stated: homosexual content. I have NEVER been so disgusted and infuriated! I was livid. I know your ticket sales clerk and manager are not responsible, and they handled the situation well. I had read and reread the content advisory to make sure it would be suitable to have my teenage son attend. I anticipated that he would appreciate the suspense, intrigue, plot twists, and mystery. The decision on the theatre’s part not to divulge repulsive content was irresponsible and negligent! You have that responsibility to your patrons.

Pioneer also posted Lino's response, in which he reasoned that no content advisory was provided because the kiss is a major plot twist and would have spoiled the show for other patrons. He also said he does not consider a gay kiss "edgy."

Lino took note of the mother's fuss over the kiss and her apparent lack of concern over the murder plot line.

"You object to the kissing, but not to the fact that they’re murderers?" he wrote. "You are comfortable with your son witnessing an enacted murder, but not a same-sex kiss? In both cases, it’s just make-believe, but how is a play that depicts murder, whether it’s a contemporary murder-mystery like 'Deathtrap' or an immortal tragedy like 'Macbeth,' morally acceptable while the depiction of a fairly innocuous, albeit same-sex kiss, is totally unacceptable?"

Lino offered to refund her "Deathtrap" tickets and said he would mark her records with "Do Not Contact" for future plays.

Apparently, the anonymous critic was not alone in thinking a gay kiss merits an advisory. Brian Urie, a Salt Lake City parent and media watchdog, agreed.