Good natured ribbing is certainly allowed and the Off Topic section is a good place for it. However anything can be carried too far and when it goes from good natured to offensive or degrading, it has crossed the line.
Keep in mind that the PM system is a means of communicating and expressing ones opinion of another member, good or bad. Grievances with another forum member should be taken to PM.
So lets get back to discussing non controversial topics in OT such as politics, crime, Ford vs. Chevy, etc.