Men: If you are unable to perform, what do you do ... see details (NSFW)

Let’s say you’re with a lady (or another man, whichever you prefer) and you can’t get it up, or can’t keep it up. (S)he’s itching for some intimacy… do you leave her/him sexually frustrated, or do you compensate in some other way (oral, toys, etc…)? What is the right thing to do? Please explain your response.