My gf thinks that we have commited some crime and is attacking me like crazy because we had a plumbing problem, and the landlord said to just take care of it, and take it out of the rent, which isnt a problem at all. Am I really wrong in doing this?
The Plumbing issue was a simple drain clog that required the plumber to drill a small hole into the offending pipe in order to get to the clog. Landlord knows he is responsible.

It depends on what caused the plumbing problem ? In my lease ,I pay cost or will take off tenants rent for this service .Unless my plumber tells me it was for tenant damage .Keep in mind I have a regular plumber and a honest one .90 % of the problems were old pipes , so I replaced at my cost. If it was hair ( keep stainer in Bathroom sinks & tubs ) or if grease blockage,diapers,ect. , No the tenant was totally charged.But it is in my lease .If landlord & tenant are happy that great .It's nice to have a good understanding with each other .