Nice picture. Am pretty sure they are both RAF. The right hand man's shoulder - or at least his clothing - is slightly skewed which has distorted the eagle.. Two RAF aircraftmen, just ACs, certainly not aircrew, but there's no indication of their trade - mechanics, clerks, could be almost anything. Almost certainly WW2 or, just possibly, immediately postwar. A lovely English summer's day. Nothing in the background to suggest location but just possibly adjacent to some East Anglian aerodrome.
Janice makes a good point about other nationalities. But there would normally be an insignia on the upper sleeve saying, for example "CANADA" and I don't think there is anything there. Otherwise probably no difference in uniforms for all the nationalities within the RAF.
Chris.