"So honey, once a month your dad earns a special treat, provided of course he has behaved properly, and has done all his chores without complaint. So I let his dicky out of his cock cage, and treat him to a tug job"
"Wow mom, so dad only gets to ejaculate once a month then? Thats pretty harsh!"
"I know honey, but it is necessary, to keep him focused on providing for our needs, and ensuring he remains eager, accepting, compliant, and openminded"
"Okay, got it, now aren't you tugging him a bit hard mom? Doesn't that hurt his penis?"
"A little yes honey, but a cuckolds tug job has to be completed in a fast and efficient manner. If it can be done to completion in about a minute, that is perfect."
"Wow okay mom, may I have a go now?"