Singer Chloe Briot was in the middle of a love scene on stage at the Opera Comique in Paris when she said her co-star sexually assaulted her.
The French baritone had done something similar in rehearsals, Briot claimed, and she had warned him to stop.
Rather than cause a scene "and throw the whole production into chaos", Briot at first said nothing.
But later when she did speak out, her co-star -- who denies the claims -- launched a slander case against her.
Briot, 32, is one of the very rare French singers to have dared complain of sexual assault in a world where her peers say complaining about harassment can be "suicidal for your career".
Even though such legends as Placido Domingo and James Levine, the musical supremo of New York's Metropolitan Opera, have been embroiled in harassment scandals, up until now the #MeToo movement has had much less impact on France's opera and classical music worlds.
Briot accused the baritone of repeatedly touching her in a sexual manner during the production of a new opera last October called "L'Inondation" (The Flood), which later toured to the cities of Rennes and Nantes in western France.
Briot claimed she was breaking an "omerta" around abuse in the profession by going to the police after the tour ended, and then going public about her complaint in a French musical review last month.
Interviewed by AFP this month, she later asked not to be quoted.
Another French soprano in her thirties, who asked not to be named, told AFP that Briot was putting her career on the line.
"It's extremely brave of Chloe Briot but I am also afraid for her -- because it's a bit suicidal.
"We all want to work," she added.
The second singer was sexually harassed by a music teacher when she was 15, and when she complained to one of his female colleagues was told that it "was all part of the job".
"When I was 19 a conductor would pin me to the wall and kiss me every time I crossed his path," she recalled.
Female performers are forced to navigate a sexual minefield, particularly early in their careers.
"It is extremely ambiguous because it can be very flattering for a young singer to have interest" from a big male star or director, she said.
"A conductor tells you, 'You sing well, you are pretty and I have an in with a festival. You just have to be nice with me,'" she said.
"There are messages in the evenings. You do not want to take the risk of pushing away an influential person..."
While the anonymous singer said most of her male counterparts have treated her with the utmost respect, "especially the new generation", it is a still problem.
Director Chloe Begou said it was all the worse when "an artist is aggressed on stage -- they have to keep going.
"You can't stop a rehearsal with 80 people all that easily," never mind a live show, said Begou, who is also an activist for equality within the profession.
Briot's case has already prompted the French ministry of culture to look at a new system to report and prevent harassment.
Yet assaults on stage and in rehearsals could fall into something of a grey area.
The prosecutor handling Briot's case, Etienne Manteaux, said the complaint "needs to be clarified to understand to what extent acting on stage could constitute acts of sexual assault."
However, the ministry took the highly unusual step of writing to the prosecutor to urge him to take the case seriously.
Briot, for her part, insists the other singer went beyond what the director had asked for the scene.
And the opera houses where the alleged assaults took place said they are redoubling their efforts to prevent it happening again.
"We have been training our team around this issue for two years," Olivier Mantei, director of the Opera Comique told AFP.
He said that in future productions casts will be briefed about the possible dangers, and victims encouraged to speak out.
When "L'Inondation" is revived in 2023, Briot will keep her role, he said. But the man she accuses will not.
"I cannot put myself in the place of the courts, but I have to be reactive to protect singers," Mantei added.
Rennes Opera director Matthieu Rietzler hailed Briot's "courage... while respecting the presumption of innocence of the accused artist."
"Her testimony obliges us to question our protocols and look at how we can improve things across the whole profession," he told AFP, stressing that there would be "zero tolerance" for abuse.