The great thing about roleplaying games like Dungeons & Dragons is the freedom you have to imagine your character doing whatever you want, but this freedom is also the terrible thing about RPGs.
Absolute freedom means figuring out all the nasty things your character can do "just because", and when some people let their imagination run wild it heads straight for the darkest part of the fantasy forest.
Redditor Gate4043 asked the fine people of Ask Reddit "D&D Players, what's the most screwed up thing you've ever done in a game?" (NSFW) and suffice it to say their responses were darker than the darkest Grimdark novel- and much more comical!
See 12 D&D Players Admit the Most Twisted Thing They've Done In-Game here (NSFW language)