"shacked up" in Chinese (Simplified)
同居（未婚情侣）
Definition
指情侣未结婚而同居，通常是非正式或秘密地住在一起。有时带有浪漫或现实的原因。
Usage Notes (Chinese (Simplified))
“Shacked up” 属于非正式表达，有时带有否定评价或惊讶，多用于口语。常指情侣未婚同居，不建议用于正式场合。
Examples
They shacked up after only three weeks of dating.
他们交往三周后就**同居**了。
My friend has shacked up with his girlfriend downtown.
我的朋友和女朋友在市中心**同居**了。
Many couples shack up before getting married nowadays.
如今很多情侣在结婚前会先**同居**。
Wow, I didn’t know you two were shacked up!
哇，我不知道你们俩已经**同居**了！
He’s been shacked up in that tiny apartment for months now.
他已经在那间小公寓**同居**好几个月了。
Their parents were shocked when they found out the couple had shacked up.
他们的父母知道这对情侣**同居**后都很震惊。