You know, I think you are assuming that going with Tiffany will automatically hurt or cause drama with Vanessa. Which I don't think is true. In a walk-through or somewhere else, the path for Sophia is called queen path I think, then there is the Tiffany path which is called something Princess. Which makes me think things will work out.
I feel as if, wirh Vanessa being a cuckquean and how much she loves her daughter, especially after the wedding and the fiance, I feel like its possible that Vanessa will see how much of a good man we are and give her blessing in the end to be with her own daughter Tiffany too.
But those are just my thoughts on how things will play out, I guess we'll see. Also I am really excited for the Tiff date, hoping for something really sweet and romantic. Wish Tiffany started earlier in game just cause I wish their was more of her.