BDSM Monopoly

My neighbors like to have very loud, rough sex.  I know this because I can hear them.

This, in itself, is really something quite remarkable.  These walls are concrete and metal and drywall and insulation all thrown together, you can't hear anything through the walls.  They could have a cinema sized surround sound system over there playing music from The Haunted on full blast, and I probably wouldn't hear it over here, that's how good these walls are.

Yet, somehow, I can hear them having sex.

And it's not just the usual moans and groans that you'd expect from normal sexual activity.  I hear things like, "HIT ME, YEAAAAAAAAH!" or, "SUCK ON IT BITCH, SUCK IT!"

Now I'm all for different strokes for different folks, and I'll admit that I've toyed with light bondage before (blindfolds, tied hands) and found it at least mildly interesting, and I wouldn't look down on these people just for their choice of sex acts.

What blows my mind is that I played Monopoly with these people.

Maybe I'm wrong in this, but in my mind, there is a distinct difference between that group of people which I imagine as being able playing an amicable game of Monopoly with friends, and that group of people who yell profanities at their significant other while wearing leather masks and having sex.  These groups are so different, that I can't imagine them ever mixing.  There's no overlap in their Venn Diagram.  I've never heard of any Monopoly fetish before, nobody screams, "BANG ME LIKE A CHEAP MEDITERRANEAN AVENUE WHORE!" or "I'LL SHOW YOU MY BOARDWALK!"

And yet, those same neighbors who I swapped properties and joked about going to jail with are over there probably whipping each other.

I should probably learn something from this, like how to never judge people by appearances, or not to make assumptions, but honestly, I'm just afraid.