My boyfriend is a blow-job lover.

Sex first, but when it's that time of the month, he wants atleast one a day and more if there's time.

My question is; every time I "go down on him" there's already pre-cum. That's normal though, I know that. So, i continue on, and all-of-a-sudden a whole bunch more comes out. He laughs 'cause it's kinda funny because it just never ends. And then more and more, it keeps happening.
And then when he finishes it's like... an ounce of cum! HOLY! I was just wondering, is it normal / healthy to cum so much, and he sometimes does this twice or more a day. Every day.

Thanks in advance