But often enough. (Actually I should look like this )
If they’re getting bored and irritated…maybe a little “variation” may help…hehehe. Actually, I admit there are occasions where I am thinking, “Good God, get off!” (pun intended), but, that’s not very often.
I just think it’s some necessary natural stimulus requirement, like having to touch the hair of a venus fly trap twice to trigger it to shut. If it shut too often or too easily, it would waste too much energy. So instead it waits until it’s sure it’s got a fly in it, hence the two-twitch rule.
The only other thing I can think of is the friction action makes the vagina more moist/ready for the sperm intake. I once read that “a vagina is a very hostile environment for sperm” so perhaps this improves that a little.