I know a man who developed mastitis.  He was definitely not breastfeeding!
 :-)  Don't know the details as to the type of organism but it required
*weeks* of antibiotic treatment.  He was um, embarrassed, I think, but his
wife, who'd nursed three, thought it was "just deserts."  I don't know if
this is so strange to get into "Ripley's Believe It or Not," but it's the
only case of a male with mastitis I've heard of!

Mary Renard, who spent years assuring women that yes, mastitis feels like
hell and then finally found out what I meant!  (It felt like hell!)