Seeing a B-52 refueling from a French Air Force C-135FR is quite a rare sight given that BUFFs typically refuel from USAF KC-135 and KC-10 tankers
Taken on Sep. 25, 2017 the interesting video in this post feature a U.S. Air Force (USAF) B-52H Stratofortress preparing for take-off at Royal Air Force (RAF) Fairford, England and then performing air-to-air refueling with a C-135FR from Armée de l’Air (French Air Force) belonging to Groupe de Ravitaillement en Vol 2/91 “Bretagne” from Istres.
Noteworthy BUFFs from the 2nd Bomber Wing (BW) at Barksdale Air Force Base (AFB), La., are deployed to RAF Fairford for a 3 week deployment supporting bomber assurance and deterrence operations.

Although USAF bomber forces regularly conduct combined theater security cooperation engagements with allies and partners, demonstrating the U.S. capability to command, control and conduct bomber missions across the globe, seeing a B-52 refueling from a French Air Force C-135FR is quite a rare sight given that BUFFs typically refuel from USAF KC-135 and KC-10 tankers.
Currently the French Air Force operates 11 C-135FRs (used as dual-role tanker/cargo and troop carrier aircraft) and 3 KC-135Rs.
Photo credit: Groupe de Ravitaillement en Vol 2/91 “Bretagne” Facebook page