Yo Sex Curse Studios, you could introduce Vicki to Simone early or you could have the protagonist decide between either Simone or Kira (I believe she is considered an adult) being present when you sign the contract.
Two reasons for this:
1) The Protagonist is a minor, therefore he would need an adult present. Usually a parent, but it can be a sibling who is of adult age if the parent isn't available. So you could have Simone or Kira present when the Protagonist signs the contract with Vicki and it enables reasoning for how the Protagonist is able to visit Vicki later in later occurrences and offers a possible threesum in the future.
2) It offers a possible threesum in the future when Vicki gets caught having sex with the protagonist. Kira is more protective and Simone is more nurturing. So at first there might be resistance or tension (similar to Simone and Kira confronting each other), but either can be won over by Kira being interested in the naughtiness of doing a porno if she is involved, while Simone can be persuaded by the Protagonist and the prospect of this being good for his future as that is what she cares about and as she is observing Vicki gets her involved into a threesum.
You could also do the Aunt in place of either Simone or Kira, which is a possibility, but unlikely as it makes little sense he would walk over to her place just to go to Vicki's Apartment/Office.