Our pom is jelous of our cat....HELP?

well our 7-8 month old pomeranian Dusty is very jelous of our 5-6 month old cat shes about the size of Dusty,,, well i was sitting on the couch watching a movie and Sammy(cat) came up and laid on my lap so i was petting her and Dusty came over and started biting her (i was petting dusty to but it didnt help).. this has been going on for a few weeks but im afraid dusty will really hurt her and i need to know how to be able to hold and cuddle with Sammy without makeing dusty feel jelous of her i love them both soo much and i just want them to get along:(((..... so can you PLEASE help me Thanks in Advance:)))