Overly affectionate

Hi, i need a little advice with specific behaviours that my son (6 years old) engages in.  

He is very affectionate to the point that he forces himself on me and others in order to hug and kiss. He is strong for his age and has been known to hurt me in order to get a hug and/or kiss.  He does this in public and becomes upset when i tell him that we cant stop in the street to keep hugging and kissing.  It is extreme to the point that he tries every 15-30 mins of every day.  I like that he is affectionate however this is obsessive and he has no concept of what is apprproate although his dad and I try to teach him every day.  He acts this way with strangers at school and at home too because he feels that this is they way to greet people.  

He also acts this way with inanimate objects such as pencils/forks/plates/the tv remote etc.  I could understand if it was a favourite teddy or toy but he seems to transfer his emotions to anything, hugging and kissing it and telling it (eg. A fork) that he loves it. 

Our son also has learning delays so trying to teach him appropriate behaviours is a very long process. 

Has anyone else experienced this with their children? If so what strategies do you use to help them? I am worried because he is vunerable and i dont want him to be singled out at school.

Thanks :)