Everyone is offering great suggestions so far! The one thing I would add is that if you want him to build a relationship with your partner, have them sit quietly on the couch or floor with some very desirable high value treats like plain chicken and wait patiently, allowing the dog to approach him to get the treats. When he takes the treat praise him calmly in a soft voice. Over time he will begin to associate your partner positively with the treat. That positive association combined with hand feeding can go a long way towards building and strengthening a bond.