Your son needs to have respect for your boundaries and your husband must help enforce this. If you feel uncomfortable with your son touching you in the way that you described, sit down with your husband, have a face to face talk and tell him that this is important to you and he needs to back you up.
Rather than threatening your son, sit down with him and tell him that you don't like him touching you like that and that you want it to stop. Be firm and clear, but not threatening.
The way your son touches you and the reaction it elicits (anger in you, a smirk in your husband) is an expression of power for which your son is getting attention. This needs to stop. If he does it again, look him in the eye and say, "I want that to stop." Do it firmly without anger. When you react in anger, he feels like he's in control.
If you have other issues with your son, read my review of this behavioral program to see if this might be right for you and your child. The program is a little pricey, but it's worth every penny, especially if you have a child who is always trying to exert his power over you.
