Translation:My father is smoking.
"My father is smoking." Is what i got corrected to. For some reason it won't let me include "a cigarette" in my answer. :/ I live in Oregon, "my father is smoking" could be smoking anything. This uses タバコ, which should be cigarette specifically. I think they probably would have something different if it were marijuana. :( I don't think I should be penalized for trying to be specific and say "my father is smoking a cigarette". I have reported it, but this is still annoying. It keeps tripping me up because it seems to be "my father or smoking a cigarette" with theタバコ part of タバコをすっています。
The more you learn Japanese, the further away it seperates from English and your way if thinking will change from direct (English) to contextual (Japanese). It's a bizarre experience as a human to mentally change like that but it'll happen if you really go for advanced :) As Bruce Lee said "Don't think, feel" :p