But this little boy was so head over heels with his sister, he serenaded her while she lay on his lap.
He cradled her face and arms and sung Joe Cocker's 'You Are So Beautiful' in the cutest way.
The baby girl stared up at her brother for the whole song, then smiled and giggled near the end, as he planted a huge kiss on her face.
The video, uploaded to Facebook on 13 June, was viewed more than 10 million times within two weeks.
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