I am a rabbit/cancer, and he's snake/Libra.

Michelle, Libra and Cancer have 50 percent chance to make their relationship work. However, rabbit and snake are compatible. So I think you both are able to make your relationship work.

However, I can't predict that you can be together forever because it's really up to you. If you bboth always make efforts to develop your relationship, then you can make your relationship last. If not, your relationship might end soon.