bedfellow

From Middle English bedfelawe; equivalent to bed +‎ fellow.

bedfellow (plural bedfellows)

1. One with whom one shares a bed.
   • 1599 Shakespeare, The Taming of the Shrew, Act 4, Scene 5.

     Young budding virgin, fair and fresh and sweet,

     Whither away, or where is thy abode?

     Happy the parents of so fair a child;

     Happier the man whom favourable stars

     Allot thee for his lovely bed-fellow.

   • 1922, Geoffrey Montagu Cookson (transl.), Prometheus Bound, page 203 in Four Plays of Aeschylus.

     Therefore, grave mistresses of fate, I pray
     That I may never live to see the day
     When Zeus takes me for his bedfellow;

2. An associate, often an otherwise improbable one.
   • 1873 They say that "misfortune makes men acquainted with strange bedfellows". The old hereditary Whig Cabinet ministers must, no doubt, by this time have learned to feel themselves at home with strange neighbours at their elbows. — Anthony Trollope, Phineas Redux, Chapter 40.
   • 2011 February 12, Les Roopanarine, “Birmingham 1 - 0 Stoke”, in BBC‎:

     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.

• (one with whom one shares a bed): bedmate

• strange bedfellows