Did Ivy only marry Raj so quickly because of his cancer? It seems pretty likely that she did, even if she isn't even fully aware of it. As she said on tonight's '90210' (Tue., 8PM ET on The CW), "I married you because I wanted to spend the rest of your life with you."
Maybe it was a hasty decision because of genuine love, but when the results came back that he was cancer-free, where does that leave them? If she married him anticipating a short relationship, followed by burying him and then eventually moving on with her life, that's a very different reality than living forever together.