Vomit Inducing cum

So I am starting to give my bf blowjobs. I’m still learning how to do it and stuff. Which he said I’m getting better at it. But I noticed something weird.

The first time I tasted his cum it tasted fine.(it weirdly tasted like the smoothie he had just drank.)

The second time was when I fully gave him a blowjob. It tasted like normal cum. Kinda salty but not bad and I managed to swallow it without trouble.

The third time It tasted really salty and left kinda a bad taste in my mouth afterwards.

This time tho. I actually couldn’t even keep it in my mouth. Once it hit my tongue I basically coughed it up while sucking him off still. I couldn’t swallow any and after I had to pretend I was going to the bathroom to wash my hands so I could wash my mouth out.

Is this normal for guys? I don’t want to make him feel bad but I’m worried that if I swallow it when it tastes that bad that I’m gonna actually throw up after. Any advice?