Please have a careful read through these guides here. They will help you work out the problem in ways that a guinea pig understands instinctively. It is not your boy's fault - you need to learn to see things from his end first and solve them in a way that makes sense to him by using guinea pig language and putting any interaction in a social frame that is acceptable to a guinea pig.
Always make sure that you tell your guinea pig first that you want him to be a member of your group, that you love him and only then you tell him what is tolerated and what not. Make sure that you then tell him that you love him again. This is how a clever guinea pig manages to deal with a problem piggy during bonding or in a dispute by asserting their dominance in a friendly way and by always making sure to make the piggy feel wanted. Then it will accept your rules much easier and will stop the hard tweaking.
Guinea pigs are prey animals, but they live in a strictly hierarchical society. If you play by the (guinea pig) rules, they will play by the rules. If you do not establish any rules, he will understand this in the way that he can get his wish to not be handled by what to him is a smelly giant predator.
" Biting" And What You Can Do
Understanding Prey Animal Instincts, Guinea Pig Whispering And Cuddling Tips
How To Pick Up And Weigh Your Guinea Pig
All the best!