My roommate and I live in a student apartment in Texas. Due to special circumstances, he wants to sublease his half of the apartment to another student for about a month. We've signed separate leases for each unit. Due to extra fees, he doesn't want to report this to management. Could I be held liable if management finds out? How bad of an idea is this?
Could I be held liable if management finds out?
You might, even if only on grounds of the implied covenant of good faith and fair dealing. The matter is otherwise hard to assess without knowing the terms of your lease.
Notwithstanding your mention of "separate leases for each unit", the lease might contain language providing joint-and-several liability which might or might not extend to damages the landlord could claim for the roommate's unauthorized sublease. Akin provisions would not be far-fetched. After all, your duty of good faith and fair dealing encompasses the common areas of that same apartment.
How bad of an idea is this?
Besides the previous point, your non-disclosure might forfeit some of your rights (i.e., pursuant to your lease) in the event that the sub-lessee's actions cause you a loss. That is because your omission deprived the landlord of the opportunity to address the risks associated to unknown sub-lessees.