Pinching

What do you do when your little one pinches your nipple and/or boob to get food or during feedings? He's breastfed almost exclusively. Tonight I was sick of it and pumped have him a one ounce bottle of bm then a 2 ounce bottle of formula. It's way past bedtime and he's now nursing, but wondering if someone has another suggestion I normally give him his Mickey Mouse toy to stop but not enough last night or tonight. He'll be 8 months on Friday