The reward he got for getting fucked in the ass by Grace was several times more than fucking her with his cock. So it looked like this was definitely the fastest way he had found so far to farm his new skill.
As he was thinking this, Grace brought her crystal cock before Ren's mouth. Then almost driven by his insticts, Ren did what the ladies had done to him many times in the past and started to give the crystal cock, that did not look like a dick and instead looked like a gem, a very inexperienced blowjob.
Seeing this Grace smiled with even more satisfaction. She then held Ren's head and made him to swallow the crystal even deeper.
As she was going all out today, Grace was planning to develop not only his asshole but his throat too. She was not planning to keep anything untouched.
Just like that Grace fucked Ren's mouth and came inside too. The liquified mana that she released was extremely tasty, so Ren actually had no trouble gulping down all of this.
