I personally don't have an issue with it, after reading the definition of "work spouse provided above. However, I am not married. When I was married I don't think I would have appreciated my husband relying on another woman for the same things he relied on me for at home, because that could lead to blurred lines, and make me wonder if that's all that was happening. On the same turn I would NEVER want to make him wonder about me. I guess you need to ask yourself, if I were married would I want my spouse to have another spouse only at work? If you and your spouse, and the other worker and his/her spouse have no issues with it, then go for it. As for what's biblical here...I don't think it qualifies as cheating per say, but again it could blur the lines.