LOL.. It's actually accurate but the thing is, like it's portrayed in this manga Avian is very easily to get aroused again.. Basically if they not in danger they can came and get hard again so many times in a mere seconds.. So they can last long if they wanted to.. So Yeah I don't think it's really problem for him because he can easily get aroused again after that, not like normal human..
The scary part about this if he came that much in one go.. He can produce a bucket ton of sperm in mere minutes..
Just imagine how much it will be if it lasted hours 💀..
Well Hitomi doesn't really mind to get dirty so I think this will be fine..