1. Engage in sex with; see go all the way, def. 2.

2. go to bed with the chickens. Retire very early, as in She made the children go to bed with the chickens. The chickens here alludes to the fact that domestic fowl generally go to sleep at sundown.

3. Also, get in or into bed with . Form a close association with, as in There's always the danger that the inspectors will get in bed with the industries they're supposed to be inspecting . This usage simply extends the sexual relationship of def. 1 to broader use.

4. go to bed. Start printing a newspaper or other publication. The allusion here is that the morning newspaper is usually printed sometime during the night before. For example, It's too late for your story; the paper went to bed half an hour ago. [Mid-1800s]