I wonder if she has him holding back from ejaculating for a similar reason to what happened in the webtoon, Brawling GO!,
when the MC in "Brawling GO!" did it, it made exponentially stronger in mind and body almost like exposive strength since it seemed to come out of nowhere
Well, I mean, aside from the fact that it is physically impossible to go a year without ejaculating because after a month or two of no sex or beating off the body will force the old spunk out in a wet dream.