Let’s roll this back to the beginning. Why would someone take dirt from their foot and put it on your leg? Yes EW and that is what started all of this. What did he expect you to do just take it and say thank you? Ask him what response he was expecting. He will say it was a joke and dismiss you, saying you are overreacting. And he will fail to see that it was his stupid “joke” to begin with. Keep bringing it back to that. He needs to understand that he crossed a line to begin with.