This is a follow-up to a previous question of mine, here.
My ex-junior at my college (I've just graduated last month) asks me to be his private tutor in preparing for a final exam in order for him to get a bachelor degree as I've achieved a while ago. The exams is a very difficult comprehensive test that tests students on all subjects the school's been teaching from the very 1st semester at college
He admitted that he once nearly failed his study because his GPA was not good enough. Then he said he's afraid that he won't be able graduate if he fails this final exam.
I'd like to help him graduate. But I couldn't bring myself to tutor him if it were just the two of us studying (me teaching him), even though the teaching job is being done in public places.
Meanwhile, as I ever heard of it, ikhtilat (intermingling of the sexes) is permissible in these circumstances: in a medical treatment, at a market, and in the class (a teacher teaching his/her class).
So, is it permissible in Islam, if I accepted his offer to teach him, and there will be only just the two of us discussing the subjects? Is it considered as khalwa as well?
I'd rather reject his wish anyway, it's so not comfortable to be with opposite-sex. Even though I'm the teacher and he's the student.
But still, I feel bad for him getting so much scared of failing the exam.
So, I'm looking for an answer that is based on Quran and Hadith for this matter. Thanks a lot.