my boyfriends best friend....

So my boyfriends best friend kept sending me messages on snap chat, (he's a pathological liar) saying that he wanted to fuck, and asking me to meet up with him saying that my boyfriend won't know. He was very aggressive and made me very uncomfortable, I told him to quit talking to me like that. I deleted him off every social media, nothing happened but I feel so icky. How do I go about telling my boyfriend? I'm afraid his best friend will lie and say that I asked him to. But I feel like He tried to take advantage of me, I don't know what to do.