I think it was version 4, (two days ago)... But maybe I picked Toru to wear the maid outfit since I had bought it previously, and so he started with maid clothes instead of his usual clothes. If that event of the mother triggers with his default clothes, maybe thats why it didn't happened?
Maybe I'm mixing memories, but surely the first time it was at Toru's house, where their parents were gone, they talked about putting the book to practice and so they did... It went to foreplay tutorial, let me remove all his clothes, and then do it with Toru all the way, then slept until morning... But no mother interruption in any moment.