Sure we can jack-it. That clears the pipes but it's not sex. Masturbation is a means to an end, that end is usually sleep. Pent up energy that would normaly go towards the act of sex needs to be released. A quick jerk and squirt takes care of the temporary need, not a long term solution. A man can get by on sex once a week, but a month, 2 months, 3 months... you will start to see a change in his overall attitude and demeanor.
Women, if you happen to read this just fuck your man. Yes there's the chance you won't enjoy it and won't have an orgasm. But it's better than the alternative.
Remember, all men are dogs and we're only as loyal as last meal/bone. Not the promise of future bones. If we know our bones are at home that's where we go. Stop giving us our bones we'll find a new place to get our bones.
Hate to over use the dog/bone comparison but it true...
PEACE