Who is Gaston Godin from Lolita and what is their importance?

Gaston teaches French at Beardsley College. He finds Humbert and Lolita a house to rent. Humbert trusts him because he is Gaston is too self-absorbed to notice anything strange. H.H. also suspects that Gaston has a thing for young boys. Gaston poses juxtaposition or perhaps a parallel to H.H.'s own desires.