Inviting friends

[mcafee_4]

Hey,

I wanted to invite a friend to my competition. He only has 2 slots unlocked and they are both occupied, but i read that if i invite him it opens up an extra slot. How does this work?
I invited him, but how can he accept the invite if he doesnt have a free slot?
Like i can only accept an invite if i go to choose a club, which isnt possible for him because his 2 slots are full and doesnt have that option.

Thanks in advance!