When you are determined to grant the applicant's request because he / she thinks you have met the syar'i criteria, and is already deliberating with your daughter and she is just silent as a sign of affirmation or perhaps more, like a smile as a flower expression of his heart or express his consent through words, then you should remain in control and control, because you are responsible for this. Do not forget that the acceptance of an application by the guardian with the approval of his daughter has not made the applicant a legal husband for your daughter, he is still a foreigner so that the laws of foreigners against girls still apply.
If before the sermon or application both of them can not be alone together, let alone sleep together, can not go alone riding motorbike or road together, not to shake hands, not to sit together together, then it still can not even once there is a received khitbah until "Ankahtuka ..." with "Qabiltu ..." occurs with the terms and conditions applicable.