I burnt my bfs penis!?

Ok ladies,

This is a strange one but I performed oral sex on my bf two nights ago and he complained it was sore and itchy afterwards, last night I went down again and afterwards in the shower he showed me and the head of his penis looks red and blotchy and very sore. How did this happen!? Have you ever had the same thing? How do I stop it? He thinks he’s allergic to me!! 😭😫

I feel so terrible. Please help