Spying becomes available when you finish the first and second brothel's quests, and then take the third one. She will ask you to spy how her new Werewolf is working in the Brothel.
As for the scenes, it happens with the female goblin. When you enter the map, three options appear; ''Pass the sign'' (you will fight the goblin),'' go another way'' (end the scene) and ''Split up(requires friend)''. Select the ''Split up'' when you have Trudy and/or Kylira as partners, and the scene will happen.
