By affairs I don't necessarily mean cheating, just romantic relationships in general. Here in Europe they aren't seen as badly as they are in the US, and are more tolerated (ie. where I live most no-fraternity rules wouldn't be legally enforceable).
Although I wouldn't reccomend them, I am not completely against them, as long as there's no obvious conflict of interest (a manager dating their direct employee) that might generate drama, or favoritism (Mike from Sales dating Jessie from HR, which could mean her backing him up in any disciplinary matter).
Overall, as long as the workplace remains serene and the employees can compartmentalize their relationships (coworkers on job, partners outside) I'm ok with them.