Macaquito is a slur used to describe Brazilians in a derogatory way. The Argentinians call Brazilians "macaquitos" (little monkeys) because they are more racially mixed.
The word Macaquito is a racial slur that has been used historically to degrade and dehumanize brazilians. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to brazilians. If you are unsure about whether or not it is appropriate to use the word Macaquito, it is best to err on the side of caution and avoid using it in any situation.