A competitor filed a patent application (it's public now). We offer the same feature but added it to our products after the application date. We found prior art that will kill the patent. The prior art is a live example from 2007 of the exact feature, the competitor is trying to patent. What should we do to make sure the competitor will not sue us in the future? Should we approach the competitor and offer not to kill the patent and in return they will not sue us (to gain an advantage on other competitors)?
It is a very rare occurrence that an infringement goes from infringement straight into litigation. There is always a dance that goes with it, usually starting from the side of the infringed party. From there discussions take place, and usually resolution is achieved. If you have a hammer knowing that you can invalidate their patent by showing prior art, then I'd probably just operate under the radar and hope it goes unnoticed by them. In truth, there's probably a good chance that their patent won't actually get registered due to the prior art so it may be a non-issue in the first place.