bedfellow

noun2

1. •
   One with whom one shares a bed.

   • Therefore, grave mistresses of fate, I pray / That I may never live to see the day / When Zeus takes me for his bedfellow — 1922
2. •
   An associate, often an otherwise improbable one.

   • Statistics and truth can be uneasy bedfellows when it comes to football, but one fact could not be ignored: neither side has a player with more than seven goals to his name. — 2011