No, he didn’t. R2-D2 is the one who said he belonged to Ben Kenobi. C-3PO said he had no idea who that was or what R2-D2 was talking about.
In the first Star Trek, little annakin skywalker shows c3po the droid he is building and almost finished with except for the skin.
correction:
In the first Star WARS, little annakin skywalker shows c3po the droid he is building and almost finished with except for the skin.