I am that man.
Provide him with proof or un-deniable reminders of the plans that were already made with you. He ^should^ revert to your plans and apologise for his error.

(I've learned to suffer the indignity of checking with the missus before I agree to anything with my mates)

If he refuses to honour your agreement, just accept the fact that he'd rather spend time with his friends and take whatever course of action you feel neccessary.
(Greencloud Wanted to go fishing on, Thu 23 Oct 2008, 14:56, Reply)