To love [something] so much that you don't release your [grip]
To love something so much that you cannot part with it
Positive
小刚拿着新买的文具盒看了又看，爱不释手 | Xiǎo Gāng názhe xīn mǎi de wénjùhé kàn le yòu kàn, àibùshìshǒu
Little Gang was unable to tear himself away from his new stationary box and gazed at it over and over
[Source]
这本书棒极了。我是爱不释手啊 | Zhè běn shū bàng jí le. Wǒ shì àibùshìshǒu a
This book is amazing. I just can't put it down.
[Source]
To be unable to put something down
To be unable to tear oneself away
爱不忍释 (ài bù rěn shì)
This is an HSK chengyu
《陶渊明集序》(Táo Yuān Míng Jí Xù) by Liáng Dynasty (梁, 502-557) author 萧统 (Xiāo Tǒng)
During the Northern and Southern Dynasties (南北朝 | Nán Běi Cháo | 420 - 589), there lived a famous writer named 潇统 (Xiāo Tǒng). 潇统 often liked to read the works of 陶渊明 (Táo Yuán Míng), a Jìn Dynasty (晋, 265 - 420) government official who grew so tired of the games of politics that he resigned, went home to live as a farmer, and eventually took to writing poetry. 潇统 once commented of 陶渊明's works that he was "unable to put them down" (爱不释手).