Strangers at stores touch/kiss my son on his cheek.

Steph • Xoxo 😘

My son is 9 months old and my husband and I take him everywhere with us. Wherever we go someone has to always touch him or kiss him. I get angry every time that happens because I don't know them or don't know where their hands have been. Or what if they have std's and they kiss my son on his cheek. Am I over reacting??? How should I tell people in a nice way that I don't like them touching/kissing my son?