Afterparty

This achievement is missable, however there is a way you can grind this out early in the game and keep your freedom of dialogue choices in your playthrough without actively looking for curse words when speaking.

To do so, when you are given the option to get the extra invite from either Lynda or the demon needing help to apprehend someone, choose Lynda, then play as normal until you get to the Durdy Hurdy Gurdy bar.

Next before speaking to Lynda you want to order "The Black Death" drink and use the dialogue options given by this drink with her. This will set up another dialogue option later.

Now play as normal again until after you speak with her boss Ono downstairs. Once you return topside of the Durdy Hurdy Gurdy you now can speak to Lynda as many times as you want with the same dialogue options and using "The Black Death" to say "Still damned. Huh." over and over until the achievement pops.

*Missable*

As far as I can tell, this has to be done in a single playthrough.

I almost lost it on my first playthorugh because I wasn't on the lookout for curse words.

Try to choose dialogue options that have the words "fuck", "asshole", "dick" and so on.

The characters not always say the curse word, but it counts, pretty easy.

Just a quick note to say that you can boost this at any point you have the option to swear (and track with the achievement progress tracker). I was short towards the end of the game, and had the option at swearing (to Satan), so swore, quit to main menu from the pause menu, loaded the save, swore again until cheeve was gained.

Here is my 100% Achievement Guide for Afterparty!

So throughout the game, now and again Lola and Milo will pop up with swear words in their dialogue options. The obvious ones.. F.. Ahole.. Dhead ETC.

Obviously, everytime you see a swear word, make sure to choose it. As long as you are purporsefully looking out for swears, you will get this achievement before you go to Satans house for the "Final" Time (When actually Wormhorn appears and splits milo and lola up.

Another trick is, every bar you enter, make you sure you have a drink with you, because when you talk to people, you can sip a drink and a third dialogue option will appear and sometimes will have swear words.

Or if your impatient, you can use Jinsokus guide (Above this one) and get Lynda a Black Death drink and getting her to say Damned until it pops.

Either way, hope this helps!

Part 1

Part 2

So if you're like me and messed up the Lynda sequence. There's a few options after to tidy up. Having a drink helps, but there's almost always an opportunity to swear at your personal demon. Multiple runs count towards the achievement, I personally got in on the second tidy up run.