2 lessees, 2 bedrooms-sublet or share when 1 is away?

[Cheekygirlie]

I am 1 of 2 people listed as tenants on a lease in a rent-stabilized 2 bedroom apartment in Manhattan (midtown west). I have lived here for 10 years, 8 of which I have been on the lease.

The owner wants to make any other people living here in my absence an official sublet, instead of a share, so that he can charge an additional 10%...which I really don't think he's allowed to do in a rent-stabilized building. But as a sublet, I think he can charge a vacancy increase during the time the other person is living here...Maybe.

My question is what am I missing? What hole would I be getting myself into by going along with the extra 10% when I think it's probably not legal? (Is it?) Or even agreeing to a sublet-status, when/if it's really a share situation. Unfortunately, all of the information I've come across regarding subletting relates primarily to single lessee units.

Thanks so much for any advice provided.