Dog experts help please?

Of course you walk your dogs so go to a Park and see how they interact with smaller dogs.Dogs love being in packs so no matter what the size there will be a pecking and dominance level established.l would not let the pup play with the adults alone at all until they have accepted the pup and can be trusted and l am not talking about eating the little one,just use common sense and can l suggest you do not introduce them on home territory as it does not belong to the pup but your other dogs.If your labs are outside dogs and Maltese inside then you have separated them completely but then you will have an issue when house training.Are you getting a male or female?A lot depends on this.You will have to walk all three together at some point and here is where you must be the DOMINANT or leader of the pack not your dogs and it can be done with different size leads.Socialize,house train pup and keep a watch on the adults as they can be rough in play but l can see no issue here and if you feel you have one ask here or take the labs to Obedience cles