I know this is been asked before and that there are several posts for almost the same issue.

But, can my son and i use the same ip AND PC to play on different realms, just not at the same time.

Since we will be using the same PC (we only have 1 in the house that can sufficiently run the game) we will not ever be logged in at the same time. We both have a master account and i know that we should have that to play from the same IP. I also know that its frowned upon playing from the same PC on different realms. But in all answers i've read it was always the case that both accounts could be logged in at the same time.

Here it wont be happening, i can even make sure that both accounts wont be logged in within hours of eachother.

If we wont be alowed to do this i think my son wont be playing at all since he doesnt want to play Hib, no matter what and i have all my characters in that realm.

Different realms from same household is considered x-realming and is not allowed. Doesn't matter if there is a pause inbetween as long as its shorter than the realm transfer timer. Even more if its from the same PC. I bet in nearly 90% of the cases son, daughter or wife is an excuse. We heard that excuse way too often during bans where it was clear already.