Need advice help

Lesley

So i been dating my boyfriend for over 1 month and i am happy he super sweet and nice however i have friend who i was FaceTiming today he out of nowhere was like i have something to show you i have no idea what is was going to be so i was show me he showed me his dick so i told him off quickly i told him i am in happy relationship wtf was he think and I’m scared to tell my boyfriend what if he considers this as cheating what if he gets mad at me i need help should i tell him