Prompt 823 - Creative

[comicfan]

Your grandmother always warned you not to make promises you couldn't keep. However, you never thought she was being serious. Until you met the odd neighbor when you moved your new home. He invited you over for a dinner but you made an excuse not to go. After finding an excuse each time he tried to get you over, you figured you would simply placate him. "I promise I'll be at your next event." He smiled and shook your hand. "Make sure you do," was all he said. When it came up, you found every reason not to go, but you suddenly find yourself compelled to go. You spot a letter left on your door that simply reads "Promises must be kept!" What happens and what did your promise make you do?