I have that excrutiating old problem. My new male au-pair is the brother of a previous au-pair I had, who now lives 50 miles away and speaks pretty good English. Her brother on the other hand, speaks no English at all yet and pretty ropey German (I speak fluent German).
He is wonderful in every way, except that he absolutely honks to high heaven. He has a shower every night, but not in the mornings, and I did buy him a "welcome pack" which was a set of bath gel, deodorant etc., nicely packaged, in anticipation of this problem (I do this for every au-pair, male or female!) It appears he hasn't taken the hint.
His German is not good enough to explain the problem, but his sister is coming at the weekend. Should I ask her to speak to him, or would that be a bad approach? (She might not have that relationship with him.) Ignoring it is just not an option - it's really seriously unpleasant, and if you walk into a room where he's just been, it smells.
Oh why do people not wash regularly and use deodorant in this day and age? I feel so embarrassed about having to raise the subject, and I just don't know how to do it delicately...