I imagine that I'm doing a standup. So I have some recoveries ready. 

> Wow, that joke was so bad I would hear a cricket if this was a movie. 
>
> Nevertheless, my grandma thinks I'm funny
>
> Strange, last time I told this joke it was so well received they told me not to come again to comedy club... WAAAIIIDAAA MINUTE. 
>
> I will shut-up now. 

Just show that you acknowledge the joke was so flat it wasn't even considered a joke and move one.