So...
Driving back from Brighton (no jokes please) I noticed a tenderness around my left nipple. Thinking it must just be a bit chafed, I ignored.
By the time I arrived home, it was getting really quite sore so I investigated the area. It looked very white - chafed skin I thought - a quick, tentative squeeze proved otherwise.
Think The Excorsist"..
A jet of what looked like cottage cheese and tomato ketchup exploded ten feet across the floor.
Seems fine now.
Most peculiar.