We rehomed a mini last week to join our other mini, Ronnie. He has come from a good home, not rescued etc so has settled in extremely well and it feels like he's been with us longer than a week already! He is gorgeous and really loving

However, Ronnie (2 years old) has not taken it too well as expected a bit jealous etc - I have read numerous articles on this but there is one issue i'd like some advice on.
The new dog will go to the toilet in the kitchen when we go out in the day (most likely due to new surroundings, feeding regime and also it was acceptable at his previous home). I don't make a fuss of the situation, just tidy it up and clean with the puppy spray we had which leaves no smell of it behind. However, Ronnie will then get up in the night, go down to the kitchen and go to the toilet in the same place as if he's marking territory.
How can we ease this behaviour in both dogs? I expect it to ease in the coming weeks, but Ronnie is completely 100% house trained and this is not normal behaviour!
There is also the typical dominance behaviour, ear nipping etc from time to time but it is getting better day by day. I also remind myself jealousy is a human emotion and not that of a dog - and am waiting for one of them to become the pack 'leader' in time.
Any help on this toilet situation appreciated!
Thanks
