Word for someone who says exactly what they are thinking

Question

Is there a word for someone who would say exactly what they are thinking. Sort of if there is this boy named Bob, and whenever he has something on his mind he just says it out loud.

Answer 1

Forthright is a word which describes someone who says exactly what they are thinking.

'free in expressing one's true feelings and opinions'

Merriam-Webster

George Orwell's contention was that it is a sure sign of trouble when things can no longer be called by their right names and described in plain, forthright speech. . . . Christopher Lasch

Quote

Answer 2

One adjective that might work is unfiltered, which Merriam-Webster's Eleventh Collegiate Dictionary (2003) defines as follows:

unfiltered adj (ca 1775) 1 : not filtered {unfiltered wine}; also : not modified, processed, or refined {unfiltered commercial publicity material —Paul Grimes} 2 : lacking a filter {an unfiltered cigarette}

As the Eleventh Collegiate notes in its definition of filter, that word can refer to

something that has the effect of a filter (as by holding back elements or modifying the appearance of something

A person who has no internal check on his or her thoughts and thus holds back nothing of what he or she is thinking may thus be described as unfiltered.

Answer 3

Blunt might be a good choice. My choice would probably depend on the connotation of said person’s behavior. You are painting a picture for your audience; what do you want them to see? Is the behavior inconsiderate? Assertive or aggressive? Or is it embarrassing? Something else? There are a lot of options.