One question that is often brought up when discussing having multiple named insureds on a policy or additional insured endorsements on a general liability policy is if something were to go wrong and the multiple named insureds or additional insureds were to sue each other, is this covered? Of course the standard response to this sort of question from a risk management perspective is that every situation is different and a lot will depend on how the contract is worded and how the insurance policy is structured. If bodily injury or property damage were involved in what was alleged you may be able to seek coverage from the general liability policy.
Source: Industry News