Swallowing

Alright, so I love going down on my dude. But we’ve been together for more than a year and a half and I have yet to let him cum in my mouth. I know he really wants to but I’m scared of the tastes lingering when I spit, but the last time I swallowed was with a one night stand and I choked and ended up spitting it out all over his dick. Any tips and tricks for swallowing and getting over the fear of it?