As we all saw in 'Born This Way', Karofsky apologizes to everyone in the glee club, including Kurt ....... so he is welcome in ND ... according to what Finn said in 'The Sue Sylvester Shuffle'....
Glee Wiki
As we all saw in 'Born This Way', Karofsky apologizes to everyone in the glee club, including Kurt ....... so he is welcome in ND ... according to what Finn said in 'The Sue Sylvester Shuffle'....