Yammo didn't like the idea of such a man having been in Zumi's life, even fictitiously. But it removed Link from the equation, just as they wanted, and she was right, it made her decision to go to Link make more sense, with having to remove the sex.
Although...
"It certainly makes more sense than going to a man who's practically a stranger and asking him to have sex with you so you could decide if you were a lesbian or not," she said softly and with a teasing smile.
Then she turned serious. "For the purpose of achieving what we're going for, it works magnificently, but are you sure you're comfortable with this story? With pretending this really happened?"