Best friend

So my best friend has had a crush on me for around 2 years now. He cant seem to get over me despite me having had 2 relationships in that time. I'm in love with my current boyfriend and my friend can't move on. I've been thinking about it a lot because of recent events and I'm wondering if the only way to let him get over me is to distance myself from him. Can he get over me if we're still this close? What do I do?