Have you figured out how to make the penis tentacle keep on fucking when you release the left mouse button?
The 3rd grabbing tentacle should unlock as soon as you fuck her anally or vaginally. Oral is not going to work (I disabled that intentionally, because having a tentacle in her mouth disables all the dialog, and I didn't want people to miss out on it).
It was a bit different in the first build I submitted, where it was indeed a bit more obscure. Are you sure you downloaded the new 1.1.1 version?
When you played it the day before yesterday, then you probably played the 1.1 version. Please try the 1.1.1 build, it contains a couple fixes.