Ronaiah Tuiasosopo

(TMZ) - Ronaiah Tuiasosopo is gay ... at least he thinks he's gay ... he's not really sure -- at least that's what he told Dr. Phil.

Phil appeared on "Today" this morning ... and dished about his interview with the man behind the Manti Te'o not-really-dead girlfriend hoax.

"Here we have a young man that fell deeply, romantically in love," Phil said of Ronaiah.

"I ask him straight up ... was this a romantic relationship with you? And he says, 'Yes.'"

Phil continued ... "I said, are you then, therefore, gay? And he says, 'Well, when you put it that way, yes.'"

Phil says Ronaiah then "caught himself" and said, "I am confused."

Phil says Ronaiah admitted to running the hoax -- but says he had a number of life experiences that left him "damaged" in many serious ways.

As we previously reported, Manti says he had NOTHING to do with the hoax and was just an innocent victim. He also told Katie Couric has was FAR, FAR, FAR from gay.