Hi there,

I work in human resources and if something like this were happening at my place of employment, I would want the employee to come talk to me. It's a good idea to start with HR to make them aware of the issue. The first thing they will want to do is for you to let the colleague know you are uncomfortable with his behavior, but it's a good idea to involve HR because they can document that you took this step which will be very helpful to you down the road if this does not correct the behavior. They are usually happy to be there as a mediator while you have this conversation with the colleague, or would likely be happy to communicate with him on your behalf. You can go it alone or involve your manager if you prefer, but HR is supposed to be there to help you with these sorts of situations and they are likely the most trained to handle it correctly and delicately. Good luck!