I have 2 one year old labs, house trained etc and they are outside when we are at work and then when we home they come in and out, but now peeing against things, they do it while I am in the same room as them and even when we have visitors. They are really great, they are well trained in sitting, lying down, come, they run 4.2km daily alongside a motorbike for exercise, have never been fed from a table so don't beg, just amazing dogs,why now this? Pse advise

Mmmmcould be they need more of your time and they are rebelling the only way they know how. Pretty intelligent dogs. Its like, look at me mom, I can do this when you are not paying attention to me !

That is my take on your situation because you say they are well trained dogs, so whatever, option is there... more time with them, they don't like being outside all day.

Tick

Are they neutered? Could be that they are maturing and marking.

If they have not been neutered then there's your answer. Boys will be boys and with 2 entire males in the house you are asking for a)Territorial marking and b)Fighting