Blowjob questions?

So my boyfriend enjoys bjs. And he was the first person I had ever given one to. I guess its a guy thing where they enjoy going deep into your throat. I have a decent gag reflex but he wants to continuously deep throat me and make me gag. I don't like it but is there a trick to be less irritated by deepthroating? And is it normal for your bf to think its hot if they make u puke?