You refer to two things or people as bedfellows when they have become associated or related in some way.
例句
It's possible to be bedfellows with someone on one issue, and at odds with them on another...可能在一個問題上與某人情投意合，在另一個問題上又意見相左。Sex and death are strange bedfellows.性愛和死亡奇怪地糾結在一起。