[usr] I walk my dog for 30 minutes at a time but no matter what, he always ends up using the bathroom inside! I wish he would left me know if he needs to go out. [sys] On no!  That is no good!  Is he still a puppy? [usr] No! He's about 2 years old now. Sometimes I think he does it out a spite when he's not getting enough attention! [qst] [None] [bhv] please give me some advices.
Hopefully he is not doing it out of spite!  Maybe you should hire a dog trainer to see if they can correct his behavior.
My dog doesn't seem to ever tell me when he needs to go outside! I walk him for about 30 minutes and he still uses the bathroom in the house.