While the two were in the middle of a reading session, Eric Reed decided to have fun with Princess Twilight and her perfectionist urges by slightly sliding her teacup from her preferred spot on her table any time she wasn't looking. She kept reacting in the way you might expect.
However, if Eric kept tempting fate by testing an alicorn's obliviousness, he could end up in a sticky situation.
This story is one of a still-growing series of stories that all take place after A Giant Adventure to Equestria. However, it is not necessary to read any of them to understand this story, but "A Giant Adventure to Equestria" does show the details of how and why the human OC Eric Reed is in Equestria even if the story isn't that great by my standards and improved writing abilities now.
If you enjoy this story and would be interested to check any of the other stories with Eric, you can find the list of all current ones here.