Was he discussing an outrageous post about biscuits by any chance?
I couldn't tell by the context, but ...
At work we call them "f bombs". As in, "I told the client over the phone how much the Council's application fee was, and his response contained a lot of f-bombs."
Perhaps that conversation was going on next door.
Yes, well. I'm a bit over caring about the f-word. Not that I swear, nor think that it is in any way appropriate - I am not a "swearing doesn't matter, it's just sounds and syllables" person - it's just that almost everyone I speak to nowdays laces their conversation with it, even when (perhaps particularly when) they are in a good mood. I care more when a fourteen year old customer calls me a different word that I didn't even know existed at fourteen. That is disturbing. (And insulting.)