How old are you ?
That question may determine what you see in the optical illusion picture below by Sandro Del-Prete. If you are very young you will see nine dolphins at play. If you are not very young you will see a couple in an erotic embrace.
What is very young? I asked my 8 year old son what he saw and he told me he saw a man and woman, but we didn't explore details of what he saw. However it has been said that younger children don't have the context to see anything other than the dolphins.
You have been able to see the nine dolphins by now haven't you? No? Come on now get your mind up out of the gutter and look a little harder.
If it makes you feel any better it took me quite a while to see the dolphins. Once you find one the rest will be obvious.