Somehow I'm not interested in ejaculating 10% of my body weight. For a 160lb man that would be about 2 gallons. Sperm banks would have to start hiring dairy farmers to handle the volume.
How long would it take to, um, deliver all that? Hmm, this is sounding better already. Being an engineer, I can't leave this alone.
The world's foremost authority claims that the average volume for an adult male is between 3 and 5cc (don't believe that old story about how they named the 80's band 10cc).
I can't seem to find a reference for how long the pumping or actual male orgasms last. So I'll assume that the orgasm and the pumping are of equal duration, and that this duration is 6 seconds, if only because it gives me a nice round numbers. Using 5cc for the volume I wind up with 50cc/minute flow rate for the average human male.
At that rate, how long would it take to deliver 2 gallons? Almost 3 hours!
Given that most of us can't run marathons, and that running one takes less time and probably happens at a lower heart rate and blood pressure, I'm guessing that most men wouldn't survive such an experience. Actually I don't know if the beetles do either, but there are plenty of other male critters that don't survive reproduction (the most depressing example probably being this.)
Alright, I've wasted enough time. May your sex never be fatal.