I think I found an exploit that needs patching!
After I went to the Vore Centre for the first time, picked up some prey and waited the three days, I released them. Directly after that I went in as a prey for the cobra woman and being curious, I failed the focus test. After the "Game Over" so to say, I got back the same morning with the prey ready to be released again.
I headed to the Vore Centre, released them, got 10000 yen but saw that the vore icon was still there. Didn't think much of it so I left and returned again the same day and got another 10000 yen from the prey. Testing it, I found out that every time you leave and return from the Vore Centre after this you get the payment even if you've already recieved it.
Hope my explaination wasn't too long, wanted to make sure I got every detail as to show maybe why this happened.
Either way, love the game since the beginning and love the update as well! Keep up the amazing work Kal! :D