work wife
n.— «Almost one in five (of 2000) respondents said they had a work husband or wife, with a quarter of chief executives who contributed to the research identifying with having a work spouse. “We’re talking about non-sexual relationships.…We’re talking very much about intimate relationships in the true meaning of the word intimate.”» —“Love your work” by Pip Cummings Sydney Morning Herald (Australia) Aug. 27, 2005. (source: Double-Tongued Dictionary)