Steve:
Bucky, Sam, Natasha, Peter Parker

Tony:
Rhodey, Happy, Bruce, Peter Parker

Bucky:
Steve, Natasha, Sam (Sometimes), T'Challa, Shuri.

Natasha:
Clint, Steve, Bucky, Maria, Bruce, Wanda

Thor:
Loki, Valkyrie, Sif, Bruce, Steve, Dr. Strange

T'Challa- Ramonda, Okoye, M'Baku, Bucky, Steve, Everett, Shuri (on a rare occasion).

Peter Quill- Mantis, Drax, Peter Parker (on earth) , Thor (though he won't admit it out-loud)