S.M.
S. - I have a five year old too. The snottiness and attitude is definatley on the rise since she was about 4 and a half. We pretty much do not permit nastiness or snarkiness and deal with it through restricting prvledges or sending her to her room for quiet time.
However, I found your description really troubling. As nasty as my daughter gets, and as large as her preference is for Mommy sometimes, she clearly loves her father and seeks his attention and approval. There is no jealously or true anger, just the occasional temper tantrum. I think that you need ot speak to your pediatrician in person (and probaly not with your son OR husband present).
I think that it is really important that we have faith in our children and trust them. Not every behavior is a discipline issue. Our kids can't always speak for themselves, and as Moms, I think you need to read between the lines to protect your child. Trust that his behavior is a way of asking you for something.
It sounds like your son is having some major anxiety and that there may be a major stressor in his life. You don't say if you are a SAHM, if he is in kindergarten, if he goes to day care, is in some activity away from the house, etc. But I would be very worried that there is something serious going on outside of your presnce to make him act out, perhaps with an adult male in his life?? Or perhaps even just bullying from other kids??
I certainly hope it is not serious, but the degree of anger you describe AND especially his jealousy over you are very troubling, and I hope you get a professional opinion about how to investigate further and deal with it. Good luck.