Amber has a choice to make.

The other twin asks, “Can you get even bigger?” You open your mouth to answer and she holds up a hand. “Not you,” she says. “She answers.”

Amber looks uncertain. “Ummm . . . maybe?”

“You can’t tell just by looking, can you?” Lara asks slyly. “You only know his length by the feel of him in your hand and your mouth.” Amber nods. “Well,” Lara continues, “we need to know. He’s clearly a tit man, which suggests one way to find out. Or else, you can take care of him. What will it be?”

“Amber,” you say, “if you’re uncomfortable with this, I won’t do it. Just say the word.”

That steadies her down. “Do you want to do it?” she asks.

“Well,” you answer, “whatever ‘it’ turns out to be, I have no strong desire either to do it or not to do it. I don’t need or want anyone but you. I definitely have my own lines that I won’t let them cross, and not just at vaginal penetration, either. What I think they’re talking about, if you think you owe it to them, then I’m in it for you. If it feels to you like me cheating on you, then I won’t do it.”

“OK,” Amber says. “Rob . . .”