Take action and quick.
We understand that “banter” exists and is more prolific in some types of business than others.
When “banter” crosses the line into offensive, intimidating and bullying behaviour then you potentially have a very expensive problem.
If someone takes offence at how they are being treated, or how someone else is being treated, you could have a harassment issue to deal with.
If you are concerned that the behaviour of your staff might border on the offensive, you need to take steps to stop it.