It is not a permissible joke to take something belonging to your brother. (Hadeeth)

Trees mist forest
Imām al-Bukhārī stated in al-Adab al-Mufrad (no. 241):
بَابُ مَا لا يَجُوزُ مِنَ اللَّعِبِ وَالْمُزَاحِ
Chapter: What is not permissible in playing and joking.
عَنْ عَبْدِ اللهِ بْنِ السَّائِبِ، عَنْ أَبِيهِ، عَنْ جَدِّهِ قَالَ‏:
‏ سَمِعْتُ رَسُولَ اللهِ صلى الله عليه وسلم، يَعْنِي، يَقُولُ‏:‏ لاَ يَأْخُذُ أَحَدُكُمْ مَتَاعَ صَاحِبِهِ لاَعِبًا وَلاَ جَادًّا، فَإِذَا أَخَذَ أَحَدُكُمْ عَصَا صَاحِبِهِ فَلْيَرُدَّهَا إِلَيْهِ‏
ʿAbdullah Ibn as-Sā’ib reported from his grandfather, who said: I heard the Messenger of Allah (salallāhu ‘alaihi wasallam) say, ‘Let not any of you take a possession of his companion in play or in seriousness. So, if one of you takes even a staff of his friend, return it back to him.’
Shaikh Al-Albānī graded it as hasan.
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