This happened in the office.
I've got limited vision on one side and didn't know this colleague was walking behind me.
As I turned round and she walked past i briefly had a warm, full handful of boob.
A brief sorry and we got on with our day, but I did notice her sat at her desk smiling later.
I once delivered a door to a customer it was wrong so had to collect it the next day the lady was holding it so I put my arm around it and grabbed her Boob very nice nothing was said