My best friend comes over twice a week to work on music. We hug to say goodbye but he will either lick my neck, cup my bum or kiss me. Sometimes a mixture of them. Every time he does I will pull away or stop the hug; he keeps it going, leaving me to stand there with his saliva. Before, I have hit him but to no success. Last Sunday, before we hugged, I asked him not to and he didn't. Because I talked to him where he could see I was serious, I thought he would understand and stop. Yesterday, he kissed and licked. I, quite seriously, said "you have to stop". He was annoyed at this and said "don't tell me not to and I won't do it." I've found almost nothing on this topic. Possible answers are he's in love with me, loves the taste of me or has Tourette's.

How can I stop this behaviour? If he does it again then I'll be saying goodbye to him for good as he can't seem to understand others' feelings and thinks of himself more often than not.

You answered your own question, "If he does it again then I'll be saying goodbye to him for good as he can't seem to understand others' feelings and thinks of himself more often than not". That's a good answer, and you should tell him that ahead of time, and don't ever hug him again!

Thank you so much for your help! That was some really good advise (even if it was my own)

Stay away from this perv! He ain't no friend to you.