Not sure I am overly concerned about the difficult child's emotions. It is just that getting emotional always backfires.
I would express your emotions/feelings with-o emotion and with little words.
I would express your feelings with actions.
So, change dinner at your home...to dinner out.
If that doesn't work....put some space between dinners...give yourself a break. Hopefully, he'll give this some thought.
Problem is, difficult children are s.l.o.w. to pick up on things.
Protect yourself first.
At some point, you might have to (again, without emotion) spell it out for him saying "You've been disrespectful and inappropriate by cancelling so often. I would really like to go out with you. I'm sure some time in the future we can try again, but not soon." Again, NO EMOTION....be like a stone faced cop.