i would say they jack off more when sexually frustrated, like teenagers before they have sex for the first time. The amount of sperm that comes has to do with how often you get off, it takes time for sperm to be made, so the longer you go without, the more sperm. Sometimes guys get off from handjob/blowjob form a girl and then have sex afterwards so that the next time he comes the amount will be far less.
That's a really good question. I think that it depends how long the guy hasn't ejaculated in a long time so it adds up. But then again when you see a really amazing girl and your having sex with her I mean you get really horny if she's your dream girl. Thus I think load is going be huge.
Scroll Down to Read Other Opinions
What's Your Opinion? Sign Up Now!generally, if a guy does not ejaculate for a while (I mean a week or more), he'll come more semen than if he's coming every other day.
sometimes it's thicker, sometimes it's runnier, doesn't mean anything profound.
It's mainly to do with the amount of time since a guy last came, after a week or more the load is generally huge
Sexual Relationships 
Sexual Health 
Most Helpful Guys