During her duet of "The Power of Love" with Des, at one point Jennifer Rush goes to sing the line "and you are my man" almost instinctively, before Des sings his revised line of "and I am your man" over the top of her. Afterwards, he smiles and points towards her to indicate it's her turn.
There's a slightly awkward moment before Des performs his duet with Jennifer Rush, as she touches his neck with her thumb - Des brushes his neck as if she's put something on him.