I can't place this one from my resources. It has four grey / light buff markings. At first I thought that it might be a Grey Mining Bee.
No interactions present.
I suspect this is a male B. jonellus - a species well known on the Bournemouth cliffs and males are on the wing right now - indeed, I saw one in Reading only last Monday
Lat/Lng: 50.71974, -1.8536
OS grid ref: SZ104911