Should I tell ?

I got a drunk text msg from one of my boyfriends friends and I couldn’t understand what he was saying but when he sobered up he couldn’t even remember what he put and then he was like “but are you down to fuck” I was just like “😲wtf” this is literally his friend from elementary they don’t talk as much as they used to but it’s still wrong isn’t it. Now I’m like thinking if the right thing to do is tell my bf and ruin their friendship or do I just not say anything as if nothing ever was said and I block him. if I block him my bf is going to ask anyways why I blocked him

Update: I told my bf and he said he was not surprised he knew one day he was gonna end up trying something. And well he lost contact w him no longer friends. Because a friend wouldn’t do that behind your back. I’m honestly glad I told him because I know I would feel guilty not telling him like he’s my bf he does deserve to know what goes on