"Let us go then, you and I"
Here's a quotation from 'Prufrock's Pervigilium', Tom, which does not hint at another personal accompanying Prufrock:
Then I have gone at night through narrow streets,
   Where evil houses leaning all together
Pointed a ribald finger at me in the darkness
   Whispering all together, chuckled at me in the darkness.
If that helps, I'm not sure.

--- On Mon, 1/25/10, Chokh Raj <[log in to unmask]> wrote:
some talk of you and me 
"Let us go then, you and I,   [Marcia's pointer to "then" is apropos]
. . . . .
Streets that follow like a tedious argument
Of insidious intent
To lead you to an overwhelming question" 
Tom, if we take the "you" of the opening line to be an aspect of Prufrock's consciousness, the streets here lead this specific "you" to an overwhelming question. In the course of the monologue, too, the only person perplexed by the overwhelming question is Prufrock, and not another person beside him.
And now these two passages:
And indeed there will be time...
Time for you and time for me,
And time yet for a hundred indecisions,
And for a hundred visions and revisions,
Before the taking of a toast and tea.
And indeed there will be time To wonder,
"Do I dare?" and, "Do I dare?"
Time to turn back and descend the stair,
With a bald spot in the middle of my hair―
[They will say: "How his hair is growing thin!"]
My morning coat, my collar mounting firmly to the chin,
My necktie rich and modest, but asserted by a simple pin―
[They will say: "But how his arms and legs are thin!"]
Do I dare 45 Disturb the universe?
In a minute there is time
For decisions and revisions which a minute will reverse.
If we view these passages apropos "Time for you and time for me", the fears and apprehensions here, and in the rest of the monologue, pertain specifically to those of Prufrock alone, and DO NOT subsume any of another person.
Incidentally, in 'Prufrock's Pervigilium', a projected aspect of self is seen apart from the self:
"And when the dawn at length had realized itself
And turned with a sense of nausea, to see what it had stirred:
The eyes and feet of men --
I fumbled to the window to experience the world
And to hear my Madness singing, sitting on the kerbstone"