Some very strange parts. ↓ is madatobi
起因是柱间在和斑喝酒的时候，跟斑说自己妹妹其实（性格）很软的，一样喝的迷迷糊糊的斑觉得有道理，但他认为的是身体柔软
It started when Hashirama was drinking with Madara and told him that his sister was actually very soft (in personality). Madara, who was also drunk and dazed, thought it made sense, but he understood it as "physically flexible."
结果在第二天在火影办公室，只有柱斑扉三人在的情况下，斑突然想起了那天晚上柱间说的：‘我妹妹（的性格）其实很软哦～’ 的发言，决定上手试一下
So the next day in the Hokage's office, while only Hashirama, Madara, and Tobirama were present, Madara suddenly recalled Hashirama’s remark from that night: "My sister (personality-wise) is actually very soft, you know～" He decided to test it out for himself.
A man of action sure moves fast, huh? XD
在柱间的瞪视，和扉间的默许下，斑把双手伸向了扉间的胸部
Under Hashirama's glare and Tobirama's silent consent, Madara reached both hands toward Tobirama's chest.
Madara thought to himself: "Hashirama was right—it really is soft."
Meanwhile, Hashirama, watching from the side, had clenched his fists and was ready to snap.
(Note: "马达拉" is the Chinese transliteration of "Madara".)
Adding a bit more to the setting:
Hashirama, Madara, Izuna, and Tobirama founded the village together in peace (I prefer peaceful alternate universes).
斑头上的发夹是泉奈给的，因为泉奈不想让他哥逃班而把所有任务推给他，所以给完发夹后就领任务出村了
The hair clip on Madara’s head was a gift from Izuna, who gave it to him before leaving the village on a mission—all because he didn’t want his brother skipping work and piling all the tasks onto him.
扉间没有反应是因为他已经感知到斑的目光停在她的胸上了，从表情就知道斑想要干的事情，想着也没什么大事就纵容了斑的行为
Tobirama didn’t react because he had already sensed Madara’s gaze fixed on his chest. From Madara’s expression alone, he could tell what was on his mind. Thinking it wasn’t a big deal, he simply let Madara go ahead with it.
What followed was Hashirama dragging Madara out of the village with a grim face for a brawl. XD
