This is normal behavior for a child being weaned. It may seem awkward to you because it may feel like he wants your boobs. Not so, he wants his milk and all he knew is that it was in your boobs (the source).
A few suggestions may help. There should be some conversation with your child letting him know that mommy is no longer breastfeeding.You can offer the child a special drinking cup that can be used in place its every time he wants to nurse. Be consistent and firm, but polite. You are setting a stage for your parenting style.
Watch the times when he does this and try to offer him milk, juice or his liquid of choice and maybe a snack ahead of time..
He needs to know that he can no longer go in your clothing or pinch you. Distract him by comforting him with rubbing of his back, or offering him a blanket, a toy or even a good story while he sits on your lap with his new cup. Draw the attention away from the nursing. Hope this helps.
Mom who has been there.