I wish women wouldn't feel they had to do this, as the organ that needs the most rejuvination from their partner is between the ears and armpits.
Do bodies fail? Absolutely, but there is more to sex then normal intercourse in CIS-HET worlds.
So if a woman's body gives out, she should not be made to feel inadequate, it means new areas and techniques need to be found to help her.
That means if penetration happens it should be very small and very short with the goal of finding the g-spot and clit and working from there.
Does it suck for guys? Well, if life gives you lemons make lemonade. Then it becomes time to explore "his body" for penetration, because men have a prostate, which can give them the same pleasure levels as a woman.
So if a woman is able to survive with a bullet or banana clip and can work up to something small, maybe she can learn the power and confidence of being in charge and finding the next set and level of sensations between men and women.
If a person can't see past this as a partner, that is ok. Just realize that person doesn't truly love the other as unconditionally as they say as actions speak louder then words.
Women please don't do this, you are beautiful as you are, as you gain tiger stripes and and your body handles life.