The Collaborative International Dictionary of English v.0.48:
Bedfellow \Bed"fel`low\, n. One who lies with another in the same bed; a person who shares one's couch. [1913 Webster] BedfereWordNet (r) 3.0 (2006):
bedfellow n 1: a temporary associate; "politics makes strange bedfellows" 2: a person with whom you share a bed