Definition: In this task, you are given a Reddit post as a text. Your task is to generate a title for this text. The title should start with "TIFU by", followed by a situation that caused humor. The title should contain 7-12 words, ideally.
Input: Text: so there i was having sex with my girlfriend. she was riding me cowgirl style and it was great. i pulled her body down to kiss her and gave her ass a light spank. then, i went for the mother of all spanks...and missed. as my title says, i slapped the shit out of my nuts. ensue worst pain ever and an instantly flaccid penis. after a couple of minutes spent laughing and writhing in pain my erection came back and we finished, but yeah. fuck...never again.

TIFU by slapping the shit out of my balls