17 month old jealous of boyfriend

my son, who turned one in July is jealous of my boyfriend who i have been with since May. We have been taking it extremely slow with him and now are discussing moving in together and so instead of throwing him in with the change of living with my parents not only into a new place away from them but with him 24/7 I thought it was a good idea to let them see each other more and get more use to each other. (biodad has never been in the picture he met him a hand full of times before he was 6 months old and screamed everytime) so...everytime I sit next to my boyfriend on the couch he freaks out. Everytime we touch in any way whether a hug or cuddle etc. he screams and tries to rip me away aggressively. How do I get it to stop? on one hand Ive always heard a child should never come in between the parents and on the other I always include him but his behavior is not ok. I have scratch marks on my face from him at this point. and im afraid his violent angry behavior will only become worse. my boyfriend thinks the baby hates him but he doesnt at all he plays with him asks for him when he is gone but to his face if im in the room acts completely different. my son wont even let him hold him if im there at all. WHAT TO I DO????