These flies seem to be attracted to light grey clothing!
No interactions present.
And crucially the 3rd antennal segment is pointed, which rules out the similar, though very local to the Surrey area, R. strigosus. iSpot has this as R. scolopaceus, which is where you would find many more pictures on the carousel.
My Flickr photos...
Lat/Lng: 53.2, -1.8
OS grid ref: SK1473