Swallowing cum

Okay soo my bf wants me to swallow his cum and I've never tried it before, so I'm kinda freaking out lol cuz it seems like it'd taste really gross, but I really want to do it to make him happy... Can anyone tell me what it might taste like? And if it's nasty what might be a good way to show that I'm unbothered, I don't wanna make it awkward by showing I'm grossed out? Lol