I'll explain it, you probably won't like the explanation. There are three different level's of sex offenders. Level three being the most serious on down to level one. The level they are classified has nothing to do with where they are allowed to be.
The controlling factor as to where they can live and who they can be around is their parole or probation officer. (if they have one) If they do, Parole and or probation can pretty much tell them where they can live and who they cannot be around.
All sex offenders do not have parole or probation officers. Those who do,if they don't get in more trouble will max out their parole and or probation at some point. Once they do that there are no conditions attached to who they hang around or where they go.
When that happens the only "stigma" attached to them is their name being on the sex offender registry. That is suppose to alert people with children or those who could be at risk that this offender is living among them.
Hope that explains it well enough for you!