(Bottom) had an imaginary friend growing up, like most kids did. His friend was (Top) wasn't his age however, he was a bit older but was still able to have fun with (Bottom) like any other kid.
Although, one day (Top) broke the news that he had to go, leaving (Bottom) by himself. It had been years since (Bottom) even thought about (Top), too busy with his work and social life now.
When he returns from a long day at work with a familiar face in his kitchen talking about the good old times, he can't help but think he's fully losing it.