I'm not going to allow my best friend to crash at my house after his wife died
Is there something wrong with you friend's place?
I feel sorry for him, but it makes me also sick at the same time and I don't want any part of that.
Your friend needs support and you should try and help him if you can. There is nothing wrong letting your friend crash at your house for a while until he feels better.
It's weak to help him. He needs to fall on his knees just like me and feel pain.
Pain makes us stronger. I am sure he knows that and needs time to heal. Be there for him and you can learn something from the experience, that will make you stronger.