Just plain mean

I come home from a long day at work to be completely ignored! Ava was sleeping but David was sitting on the ottoman playing. I walk in and say 'Hi David, how are you feeling? I missed you today.' No response. So, I clean up around the house, talk to my Dad and go back to Mr. Mean for a kiss. I give him a kiss and he freaks! 'You are making bugars!' is what he tells me - what? My dad leaves and he barely said good bye to him. So, now it is just David and I. I go to the bathroom, get him a tissue and when I come back he tells me he does not want me to be home. He goes on to tell me he did not miss me and will not think about me anymore. Again - what? When he was wiping his nose, he got a piece of tissue in his mouth and he proceeds to SPIT on my floor. I warn him once but he continues to do it. My next move is to put him in time out. Now he tells me he wants to be with MomMom and Gramps. I tell him that even though he is very mean, that I still love him and he has made me VERY sad. Ava woke up before time out was over so I went up changed my clothes and got her from her crib. When we came down, his time out was over. He treated me a tiny bit better, but was still a big brat. I do not know what his problem is/was. All I do know, is that he is breaking my heart. What happened to my baby boy?