bite my tongue

"And again, that fire that Kengkla had sparked in him earlier returns, daring him to lash out at the boy, to give up being the bigger person for once, but Techno knows better. He knows he has goals, he has dreams. He knows what he has to do to achieve them. And so, he keeps on walking, he bites his tongue, and he silently prays that he'll never have to see Kengkla after today."