Originally Posted by Airdres

Thanks a lot for the replies.
I have thought about the note from my friend and all that, I will carry it just in case (I can't bring him to the Airport).

While I posted this here, I also wrote to both Expedia and Singapore Airlines and fortunately there will be no problem. Expedia was unable to give a definitive answer (don't really blame them though), but Singapore thankfully did. I will paste the answer they gave me here in case someone else finds him/herself in the same situation:

"Dear Mr. Airdres,

Thank you for your email.

In reference to your query, please be informed that credit card
verification applies only to the reservations booked and ticketed through
our Reservations Office or our website.

As your reservation is booked and ticketed through a travel agency, the
credit card verification procedure would not be applicable on your booking.

Please feel free to contact our Reservation Call Centre in USA, at + 1 800
742 3333 (24hours / 07days) for any further clarification or assistance.

Thank you for choosing Singapore Airlines.

Sincerely,

Leena Nathani
SIA USA"

Got to love customer service when it's quick and helpful!