Toby has been a bit teenage lately too
Probably a combination of his age and the puppy. His recall is still quite good but he started wetting at night now and then and chewing.
I do think they go through this phase quite commonly. Do you have a crate and if so is it large enough for him now (if it was only used while he was a pup)? If you do have a crate, it might help to crate him at night as far as toilet training goes.
We've crated Toby for a few nights, it hasn't bothered him much and hopefully he will get the message about toilet training again (I think perhaps the fact that the pup has accidents now and then has affected him...there might be scent from the pup too).