​Gypsum's scheme worked perfectly.
Topaz was becoming very distraught; she paced, wailed, wrung her hands, and actually shed some tears. Riotori can cry, but only prolonged strong emotions can bring that about. Never pain.
He crept up the hill on the opposite side of the Old City. He expected a random glance in his direction to reveal his presence, but it didn't happen.
"Hey! Anybody got anything to eat?" His greeting accomplished what he wished. Even Feldspar jumped a little.
Topaz shrieked. Riotori could go their whole lives without hearing one of their kind shriek. And those that did hear it never wanted to hear it again.
The shriek was accompanied by action. She assaulted her future mate. Relief, surprise, anger, all spurred Topaz to violence.
She jumped right onto Gypsum's chest and bore him to the ground on his back. This was painful and awkward; the armor on his back felt like...well, like what it was: a pile of metal full of edges, sharp points, flat surfaces, and over a foot thick.
Topaz beat him around the head and shoulders, thumping and shouting, using language her father had not known she knew.
Beryl enjoyed the display. She was not surprised to hear her sister's profanity and she considered Gypsum's little trick more than enough motivation for the violence.
Feldspar and the other two males simply watched. They, too, understood her reaction though it took them a bit by surprise.
Gypsum was more than a little surprised. As he lay partly on his back and partly on his side, he reflected that his little trick may not have been his best decision.
Topaz's anger arose from the relief that overwhelmed her plus the embarrassment she felt for being so startled and so relieved.
Feldspar and Gypsum had been trained by their father and uncle that females were to be treated with kindness and respect, always. So he did nothing more than defend himself from her anger and do his best to not be injured.
However.
The twins' mother and aunt also taught them. Their uncle had given their aunt only the seeds for daughters, and the twins' cousin were more than a year older than the boys.
They roughhoused regularly in play.
There is a peculiar genetic trait in female Riotori. When they manage to attain a physical advantage over a male, in play or in an actual hostile encounter, there is an unconscious but overwhelming urge to actually dominate the male into submission. The female will, without warning, begin to intentionally inflict pain on the male to force him to submit.
Feldspar and Gypsum encountered this one each during rough play with their cousins. With their indoctrination of respect and kindness for women, they did not "fight back." The assault continued.
That's when their mother and aunt, observing the exchange finally stepped in verbally.
"Boys! You have been well-trained by your father and uncle, but you must also know when too much is enough, and assert yourselves!"
They did not have to be told twice.
Now, that genetic urge suddenly overtook Topaz and she was not even consciously aware of it. But her assault, originally frantic random swats and shoves, became intentional attempts to inflict pain—enough pain to force him to cry for mercy and submit. And she became silent, except for labored breathing.
At that point, too much was enough.
He warned her with a growl. She either did not hear or did not care.
Seconds later she found herself sailing through the air and then landing hard a few yards away.
Before she could rise, Gypsum was upon her. He put his tusks against her throat and muttered so quietly that only she could hear.
"If you are done, I will say sorry. If you are not done, then we are."
He stood up and offered his hand to help her rise. She took it and stood up, looking as chastened and apologetic as a Riotori can.
"No, my lord Gypsum, it is I who should apologize. My instincts took me over."
He took her hand and rubbed the furry back against the outside of his upper tusk; it was a sign of forgiveness, admiration, and lasting affection.  It thrilled her.
It also pleased their audience.
Beryl had stood close to Feldspar throughout the tussle. When Gypsum accorded Topaz his gesture of affection, Beryl took Feldspar's hand in hers and smiled at him.
He returned the smile, but he was distracted. Already he was thinking about his own trial tomorrow.