The old hand-in-water trick

Abby takes her things to the guest bedroom, and she then hops onto the bed and lays down. She soon dozes off, and she stays asleep for the next couple hours.

However, while she is in the middle of her nap, Mark and Rick creep into the room, the latter of them holding a bowl of warm water and the former has his cell phone out.

"Ready?" Mark asks

"Ready," his younger brother replies, approaching the bed with the bowl, "This is going to be sweet."

He then places the bowl of water on the bedside table, and he carefully places Abby's hand in the bowl. "Now... we wait."

They do not have to wait long. Less then ten minutes later, a huge spot begins to develop on the front of Abby's jeans. Mark smirks and takes several pictures of the result.