Tiana, you seem quite confident that you do not want or could handle a monogamous relationship. Bob seems quite confident and convinced that he does and won't be healthy in a poly one. Unless you plan on denying a part of who you are, I think you should tell him. If he is as adamant as you say then you truly won't be compatable for a long, stable, and healthy life that could include children.
Your parents and Bob will likely be discussing how to bring you around to a mono way of life so be aware of that.
Playing the Game of Life with Monopoly rules.
Monogamy might just be in my genes
Poly Events All Over