Be a man, go by yourself.
Never believe anyone who says they'll go away with you, specially if they have to pay... or at least plan to go by yourself.

Sorry mate, my wife's having a baby.
Sorry mate, I can't afford it right now.
Sorry mate, I need the money for X, Y, Z.
Sorry mate, I'm selling my house.
Sorry mate, I'm saving up for the wedding.
What did your friend say?