Clearly the Klingons know a thing or two about relationships. If you survive one of those, you'll definitely know where you stand!
Seriously, using the example of co-workers, it's generally a bad idea just because you still have to work with the person even if there's a nasty break-up, or quit your job, but on the other hand, I know couples who met working together, got married, and have stayed that way for years, so things can also go really right.
It's even riskier to date your boss, as the legal system frequently gets involved, but yeah, sometimes that works out, too. (My niece-in-law had a kid with hers.)