Legal Question in Real Estate Law in Maryland

He can't stop you from moving, but he has individual rights as a lessee and if he wants to stay and pay the rent he can. The "early termination clause" as you describe it offers you no more protection than if it didn't exist, because you're still exposed to potentially paying for the full lease period if the landlord doesn't find a new tenant. Actually it's worse than nothing because if you broke the lease and the landlord was able to find a new tenant right away or after 1 month of vacancy, you'd owe less than under this clause. The law requires the landlord to mitigate damages from a broken lease by making a good faith effort to find a new tenant or lose the right to hold the departing tenant responsible. In your situation if you leave and the ex stays put but doesn't pay the rent, the landlord could sue either of you for the unpaid rent, but if he did you'd have a good claim for cross-suing the ex. Of course, if he's unemployed or otherwise financially irresponsible, you could get left "holding the bag".

So you should make it clear to the ex that if he wants to stay he better be prepared to pay the entire rent. Also, you might contact the landlord and offer to pay the 2 months in exchange for a full release from any further liability.