What the barging is really about
When your first dog shoulders between you and the newcomer, whines while you stroke the other, or suddenly produces a toy and shoves it at your hand, he is not plotting revenge. He has learned two simple things: attention is valuable, and interrupting has historically made it arrive. The behaviour is worse in the first weeks with a second dog because your first dog is also doing maths — the resource he used to monopolise now gets divided, and nobody has yet taught him the new system still pays him reliably.
Pay the waiter, ignore the interruption
Reverse the economy. When you fuss the second dog, watch for your first dog lying down, watching calmly, or settling on his mat — and let praise and treats rain on that dog. If he barges in, stand up, fold your arms, and let the fuss stop for everyone for a few seconds; attention vanishing is a clearer lesson than being told off, which is still attention. Within days most dogs start offering the behaviour that works: parking themselves visibly and waiting to be paid for their patience.
Guarantee one-to-one time every day
Competition shrinks when neither dog depends on stealing moments. Schedule short solo sessions daily — a ten-minute training game for one while the other rests behind a gate with a chew, a separate short walk, even individual sofa time in rotation. The dog who knows his own session is coming can relax during the other's. Give each dog some things that are never shared: a particular game, a grooming routine, a route only the two of you walk. These rituals tell each dog his place in your life was not reassigned to the newcomer.
Structure group time with mats and turns
For the times everyone is together, teach both dogs to settle on separate mats a comfortable distance apart, and practise in short, easy sessions with treats delivered to each in turn — name, treat, other name, treat — so hearing the other dog's name predicts their own reward coming next. Keep greetings when you come home low-key and equal: a calm hello to the room rather than a flood of fuss for whoever reaches you first, which removes the daily contest at the door.
Take the competition out of feeding and arrivals
Jealousy spills over from the day's other contests, so audit them. If both dogs eat side by side with one finishing first and hovering, feed them apart until the pushiness settles. If the flashpoint is always your return home, change that scene first — it is the highest-value moment of the day and the one where rivalry rehearses itself daily. Spread calm rewards through ordinary moments instead: both dogs lying quietly while you read is worth paying for, because that, and not the doorway scrum, is the behaviour you want repeated.
Watch for the version that is not simple pushiness
If the interruptions come with hard staring, freezing over you, growling when the other dog approaches, or guarding your lap like a possession, treat it as resource guarding of a person and get a qualified behaviour professional involved rather than drilling obedience around it. Ordinary pushiness softens as the routine beds in; guarding escalates when it is practised.
KinsLe's Family Sharing helps because each dog's solo sessions, mat practice, and fuss rotation can sit on their shared profiles where the whole household sees them, so nobody accidentally spends all evening rewarding only the dog who demands loudest.