When she actually took him seriously and went to check for ways he could escape, Frank lifted his hand to his forehead and took a deep breath as he shook his head. The trouble of course was that the two of them were both too close to the other in many ways despite only having just met that it was eerie. There were broad similarities such as in the way they each babbled when dealing with difficult situations, were pretty much emotionally the same age (and that wasn't a day over 14) despite what the calendar said, and spoke their minds when something was important enough to be said, however uncomfortable that might be. They were each the center of their social group and each of them hid behind so many masks it was hard to get through to the real person - the scared fragile person - inside.
They were both also, as John could have attested to were he around, from their own little planets where being stubborn was the primary virtue. Headstrong was a word often applied to Frank and it applied just as firmly to Amelia so he wasn't fooled in the least when she went back outside and let him go into the bathroom. Shutting the door, he leaned against it and looked at the ceiling, wondering how long it would take him to dig his way out into the bedroom through the sheetrock and make good his escape. The thought was amusing enough to make him smirk as he took care of the most pressing need, flushed, and ran the water to wash his hands. It was then he spotted the decorative wide-mouthed vase sitting innocuously atop the towel stand and picked it up, casting a devious look over his shoulder towards the door.
"See how you like a surprise," he muttered as he filled the vase, then turned off the taps and dried his hands. It came to pass that as he opened the door and spotted her standing there, he reached and snatched up the vase, flinging the water it held at her.