Got kissed by another guy

Hi all so i went to a club with my new boyfriend actually he s not really my boyfriend but we kiss and hold hands so a guy friend asked me to dance with him on the dancefloor and my bf was fine with it. That guy kissed me and i was dizzy i didnlt back off and my boyfriend made a a huge scandal and now he 's blocked me on everything i can't contact him i wrote him a letter but i t hasn't arrived. What do i do ?