I'd heard that expecting fathers can gain "sympathy weight" along with their pregnant partners, (Rob gained 26 pounds, I gained 35) but I hadn't realized they could experience morning sickness too.

But the 2006 Pregnancy Book, issued by the Department of Health in the UK, notes that fathers-to-be can experience every symptom of morning sickness that an expectant Mother feels.  The most common ailments reported are nausea, indigestion, and sleeplessness, and the article notes that, though they're likely stress-induced, they're no doubt just as uncomfortable.

I don't know if I'd define that as an actual illness or an attack of the nerves.