What do you think of a husband going out for lunch with another woman (who's an old close friend and not muslim, unmarried but in a relationship), just the two of them but in a restaurant in a public place. The husband tells the wife of course and he has nothing to hide. In fact he asks the wife whether she wants to come along and she says no (probably mad) so the husband proceeds anyway.
Main question is it acceptable in islam for a married man to meet another woman and catch up, just the two of them?