Hi Rafster, you are right, there is a url exclusion feature which was added 4 years ago, and is not useful when trying to combine tags. Hopefully exclusion filters will be added in the near future.
However, I don't completely agree that this is the main problem. Granted that excluding certain adult tags would help... but this approach alone would be similar to burying one's head in the sand, or sweeping dirt under the rug so that you don't see it. The problem is still there, is not going anywhere.
I believe the solution is not hiding potentially abusive adult content from some viewers, but examining scrupulously such games and actually enforcing the rules whenever illegal / questionable content is found. Not closing your eyes, but opening them wide. It's not a blindfold what we need, it's a magnifying glass ;)