Are desks distinguishable? If not there are $\dbinom{14}{2}=91$ ways you and your friend can sit together at the same desk.

If they are there are $\dbinom{8}{1}\dbinom{14}{2}=728$ ways.

I assume the seats within the desk are indistinguishable. If they are distinguishable add another factor of $2^8$ to get $186368$.