It's a demonic skill. You get it by progressing the training girls in the tavern.
thanks
Why can't I play for a long time? Aren't those the girls at $ 10 a pop?
Can you explain this a bit more? Which girls are in the tavern, and is it called Tavern? Because the only place i have is the bar and inn. I still can't seem to unlock it.
How to get more girls