To see what the other person is good, we must first understand what he doesn't like. Apart from this, even if he is sent away, he won't be very repulsive. Besides, he is a lecturer after all, unless he asks not to send anything that will harm the teacher's example, such as direct money, or alcohol and tobacco, unless he says he likes it very much, that's fine, otherwise don't. Or let people around you beat about the bush.