sucking dick tips 🤷‍♀️🤷‍♀️

my boyfriend loves cumming in my mouth , and i love it too and the thought of being able to swallow it all for him ( kind of a kink idk ) anyways , the thing is i can’t swallow it , i gag everytime i try and he always just ends up letting it go all over my face instead of in my mouth , can somebody give me any tips on not gagging or being able to take it all and then gag or something ??