How do you know when it is time to stop having sex?

1.) When your wife is mad because her sons keep coming out missing an eye.

2.) When she can't walk in a straight line anymore.

3.) When your wife can eat you, but now you can feel her lungs.

4.) When her prostetic legs falls off.

5.) When she become numb.

6.) When she starts watching TV.

7.) When you start a fire!