Life causes stress... it is the way of things. Yes, jobs certainly cause stress. Shocker, I know, but a lot of people do not like being handed off to a bordello and used as a fuck toy by anyone who wants to have a go. Most things in the game generate stress.
It is your job as overlord and master to combat the stress and keep it under control. Ways to combat...
Keep the mansion clean (think around 70% is the cutoff for where it switches from not really causing stress to generating quite a lot of stress).
Sedation (the spell). Pretty much wipes out all the stress on a single slave when cast.
Giving someone the day off. Yes, if you do not want to cast a spell on someone, from time to time you may just need to set them to "rest" for a day or more.
Put someone to work as a Headgirl. Oh, and by default the game is set up to have this job do absolutely nothing (dumb, I know). So make sure you go to "mansion," "mansion settings," and change the "headgirl settings" off of ignore. Setting it to "Patronage" will cause your headgirl to reduce all slaves' stress by some amount every day. (just headgirl and keeping the place clean are often enough to manage all stress from just regular days... not including fighting stress and other things you do to pile on extra stress)
When interacting with a girl there is one action "pat head" that lowers stress a bit each time you click it (until the slave gets annoyed and decides you are over using it).
As was mentioned, certain clothing reduces stress daily on the slave wearing it by a little.
When you do go out and fight, make sure you have 3 supplies along in your bag. Once per day you can use those supplies while traveling ("rest and eat"), and this lowers stress on the 3 slaves traveling with you quite a bit. Personally I tend to do pretty much all of my fighting and as the very last move before I re-enter a town use the supplies then. That way my slaves end the fighting with very little stress. Then just do not go out on another long fighting venture until the next day.
Oh, side note, I'll add that slaves sometimes demand varying degrees of luxury. If the new day's report tells you things like a "quality of life" complaint, well that is a-whole-nother matter. You need to give that slave more luxury (better room, better underwear, gold ring, or go into customization and turn on some luxury rules for certain slaves). Just "having" supplies does nothing for a player. It is only assigning them to be used in one way or another (like in those luxury rules) that matters.
@alex2011
As
@scrumbles said...
Click the slave in the list; click the "talk" button under her sleeping location; click "investigate X's potential" in the pop-up dialog.
This will randomly determine something you must do/provide to the slave and tell you what that something is. When you eventually accomplish this request the slave will then level up. Until you do this the slave is xp locked.
Sidenote, the game can be very ridiculous with level up requests. Save before you find out what the slave requires. You'll often need to hack your way around with some form of cheating. Save scumming is the least code/mod required way to do so. There is a potion that can reset the demand as well, but this is not even available until one has done a decent bit of mansion upgrading.