If someone caught you masturbating how would you react?

I suppose a lot would depend on your personal views about sex and the circumstances.

I think I'd be ashamed to the point where I would literally crawl inside myself and disappear.

Not having any romantic/sexual partner I'd be unlikely to have a positive situation outcome from being caught doing it.

Even if I did have a romantic/sexual partner I don't know how I'd react. I guess not having felt genuine romantic love for a very long time makes it difficult to think how I'd deal with it.