get in(to) bed with (someone or something)

To enter into a relationship with someone or something, often but not always one that is considered unseemly for some reason. I don't trust Albert because I heard he's gotten into bed with the mob. The company is considering getting in bed with some of its suppliers, which may help to cut costs. Do you really think all of those politicians have gotten into bed with the oil industry?

get into bed with someone

If one person or group gets into bed with another, they make an agreement to work together. There's not much chance of them getting into bed with a bank of that size. Note: You can also say that a person or group is in bed with another, meaning that they are already working together. He was clearly in bed with the government. Note: This expression is usually used to show disapproval.