All Bikers are not Bad!

A drunk walks into a biker bar orders a drink then sees three men sitting at a corner table.
He staggers to the table, looks squarely at the biggest, meanest, biker, and says: 

'I went by your grandma's house today and  I saw her in the hallway buck-naked. Man, she is one fine looking woman!'                 

The biker looks at him and doesn't say a word. His buddies are confused, because he is one bad biker and would fight at the drop of a hat.          
The drunk moving in closer the leans on the table and says: 

'I got it on with your grandma too and she is good, the best I ever had!'

The biker's buddies are starting to get really mad but the biker still says nothing.
The drunk then leans right up close to the biker’s face and snarls , 

"I'll tell you something else, boy, your grandma liked it!'

At this point the biker stands up, takes the drunk by the shoulders looks him in the eyes and says...'Grandpa,.......... Go home!'