The first thing a puppy needs is consistancy...and it doesn't sound as if the two of you are giving the exact same consistant signals to the pup. If it is ok to mess on the carpet for one of you and not ok from the other, the pup will remain confused as to what is and isn't allowed.
Whomever is the most consistant about what is allowed becomes leader of the pack...if no human steps up to become the pack leader the pup will continue to do whatever it wants where ever it wants whenever it wants...for the rest of it's life.
A "come-to-jesus" conversation between the two humans needs to happen asap. Who is in charge, what is allowed, what is not allowed, what training is needed, who will train and how often, what kind of dog is wanted in the house (companion, guard, hunter, etc.) all need to be agreed on and, possibly, a written contract between the two humans needs to be signed by both.
If the two of you are not able to train the pup on your own, take the pup to a class and learn...the pup will really enjoy it.
If the two of you are not willing or able to spend the time, patience and expense necessary to mold the pup into the fine dog it has every right to be...give it a home that is willing to do the work necessary.
I have professionally trained many breeds of dogs for many types of households for many types of duties...Someone needs to step up now for the sake of the dog...a bad dog is created by it's environment, it isn't born that way.
You always get the dog you deserve! Dogs are not born knowing what is expected of them, they need (and crave) firm, gentle lessons from someone in charge. Whomever is in charge must be willing to ALWAYS be in charge. This is what the dog is looking for.
Good luck, to you and the pup.