Boss Issues

I've heard through the grapevine that my boss thinks that myself and a coworker are involved romantically when we are not. First of all I have a boyfriend and am not a lesbian, second, we are like sisters and so we act as such. It's rare to find such an amazing friend. This has put a wedge in our friendship as we do not know what to do or how to act. I'm so depressed over this as she was part of my reason as to why I loved going to work so much. Her friendship made me MORE productive and now I hate being there when we are scared to even communicate while he's around. PLEASE HELP. Please give me some advice... I feel like I'm losing one of the best friends I've ever had and it hurts