You knew him as simon, not Ghost. So he pretends to not recognize you

"I was thinking that maybe next time-" Ghost says before getting cut off. You walked into the room scaning the place.

"Do you know them? They're new" Soap says looking at ghost his eyes on you

Ghost gets out of his trance, looking down before looking back at you. "No,I have no idea" Ghost say realizing his identity could be leaked.

He wonders if he shoukd tell you or not.