There are those PDF's that tell the main options with classes, not all of them human, so there is some about the races too. I will get to my computer in the next one or two day, so I will give out more helpful Rules... until then:
The main rule is that the DM (me) have to present problems, and sometimes solutions - and there are MOVES. Which is just a word about situation, where the player usually has to throw 2d6, if it is 10+ then it is a success without problems, and if it is 7-9, then it happens, but leaves some opening for something.
While there are things that give out bonuses to these throws, any extra skill, item, or option is mainly giving out new MOVES...
So, having a weapon gives you a MOVE to do damage with said weapon, while having an armor leaves you with a MOVE to stop the damage. Any item makes you able to either use it as intended, or sometimes you loose it in exchange for a full success when you throw 7-9...
For our roleplay next to the rules that are in the PDF's, I only add the possibility to everyone get to use their sexiness, mainly as a basic move in any situation, either before (so making it more likely to get success) or after (when it is not a full success, so you try to make it sexual - which usually opens up a new possibility for problems) -> so, this is where you can loose your clothes, or flash someone, or just about anything that is making you feel kinky, but still able to do anything you intend to, including an attack, or climbing a rope, or anything, really. This basic move can change with every situation, as in itself, the Basic Move is Use Sexyness.
Doing anything sexual for a longer time - including doing a strip-tease, or trying to pick up someone - is an Advanced Move, meaning that in itself is a full action, taking long minutes, or even hours, days.... But their effect could be deeper or longer lasting.
Then, there are the special moves. Every player with a character should think about what their characters special (like being from a specific race, or having some class) sexual extra, if any. This would be only one thing at level one, but you do not need to have i, you can get it in the game... This is the kink or focus - or fetish - that is one of the main details of your character's sexual side, usually making problems or solutions, but really differs from the norm.
I would consider Big Bouncy Breasts a special move, but you have to think out what it makes you able to do... As in what extra it gives if you use it, and throw 7-9, and what it would mean to have full success with it? 10+... I can help come up with in-game details, but everyone have to come up with their own feature.
This is something that would be for the first 5 level, but it is possible that I would be giving out other ones as the game progresses. Either as a gift, a curse, or just an effect of doing something... It is possible to have items, places, or other things give these kind of moves for a while.