Duncan's second speech after the entrance of Lady Macbeth is literally just a formality, a greeting with his hostess. Duncan acknowledges that their love for him, as their king, may cause them the trouble and inconvenience of having to host him, but he is appreciative of their kind hospitality.
This speech is ironic because the reader knows she is not an "honour'd hostess" or a hostess who is going to a lot of trouble to help her guest, the king. At this point, Lady Macbeth has already stepped in to ensure Macbeth is on board to kill Duncan. When Duncan talks about how much Macbeth and Lady Macbeth love Duncan, the audience smirks at Duncan's stupidity for they are scheming behind his back.