He's mostly feeding you a line of BS.
Certainly, being aroused for a long time without ejaculating can be quite uncomfortable--the colloquial term for this is "blue balls" (it's actually temporary inflammation of the prostate gland). As a man I can assure you that that discomfort is quite real, but that discomfort can be totally relieved by ejaculation, and feel free to remind him that he can always take care of that himself.
Also, you might want to reconsider your love for a guy who would try to coerce you into having sex before you're ready.