Chris Brown -- Did He Tattoo Rihanna On His Neck?

Chris Brown insists his brand new neck tattoo is NOT a bizarre homage to Rihanna -- but if you look closely, the resemblance is uncanny.

The last photo we've seen of Chris without the tat is dated August 30th and the above photo was taken on September 1st, so CB got the ink job at some point between those two dates ... nearly a week before Rihanna kissed him at the MTV VMAs.

Sources really close to Chris tell us any similarities the tat has with Rihanna's face are purely coincidental -- "It's a random woman."

But we still gotta ask ...