People who ask for advice often end up regretting that they asked. Being asked is not a license to lessen your caution.
If it is practical and not embarrassing for the person, immediately pray with the person that the Lord fulfill his promise in James 1:5 to give the person wisdom. Should you then feel to add anything, introduce it by such remarks as, ĎAdvice is only talk. Itís action that is hard. Just as Peter was sure he would never deny Jesus, if I were really in your situation I might end up acting sadly different to the way I expect I would. Tell me if Iíve misunderstood the situation, but what I would like to think Iíd do would be something like . . .í
For a more detailed explanation of the dangers of advice-giving, see
A First Aid Course For Emotions