Yeah just be honest

"Wow, that's pretty incredible," he said as Inez stopped the cart in front of one of the bathrooms. "I don't really know what to say beyond that though."

"I haven't spoken to anyone about my past in a long time Jack," she said as her concerned disposition changed to one of positivity, "I'm just glad someone asked."

"Yeah I don't think I could survive by myself at 19." he said making a joke.

"I don't recommend it," she said giggling.

"So...um, how long are you still going to be here at school for?" he asked, wondering how much longer he could stay before he had to go.

"Oh I leave at around 6pm every day, you don't want to stay and wait for me." she said, deep down wishing that he would, but knowing that he can't.

"Yeah my parents would wonder where I was," he said. He turned to walk away but his bladder stopped him. "Oh um, could I use the bathroom before you get started in there?"

"Of course sweetheart," she said as she smiled at him.

Jack turned around and went into the bathroom. While he was peeing he had an thought. Why doesn't he test his theory about Inez liking boys underwear and leave his boxers on the toilet seat? His intentions would be blatantly clear to her then. Who just forgets their underwear in the bathroom. It would surely make for an uncomfortable conversation tomorrow if all his assumptions about her up to this point have been wrong. She could just be polite and not want him to suck her tits at all; what a shame that would be.