She had had enough.
The two of them had built their original prototype together. It was a labor of love, conducted over the many years of their relationship. Marion had fond memories of the two of them huddled closely over their design, hands and hearts nearly touching. It was Marion's idea to use water to operate the device; Carl's idea to use a toilet as a method of camouflage. It figures, she thought. Lord knows he spent enough time in the bathroom.
But it had worked.
It had worked beyond their wildest expectations. Their first trip had been just a brief jaunt to last week, Marion sitting on Carl's lap as he flushed. They were giddy with excitement at their success, and celebrated like they had when they were first married.
Carl was eager to begin leaping back and forth through the past. He had begun making longer trips, visiting long gone family members, and generally stalking famous historic figures. Marion advised caution; who knew how much the past would be changed by their mere presence? But Carl was a big kid at heart, with no thought to the havoc he might cause.
And the bastard would not put the seat down on the time machine.
Marion really had no choice, she told herself. It was for Carl's own good. She set the time machine for the appropriate time; it would disappear forever. Then they could go back to just being an old married couple. Except that Marion hadn't counted on Carl figuring out her plan. She hadn't expected him to burst in the door.
She certainly hadn't expected her husband to throw himself on the time machine as she flushed the time machine back to 15,000,000 B.C.

The prompt is: