Just that really. I want to add it to a meal for DS (PFB, 7.5 months) because I'm crap at cooking rice and he's had so much pasta it's coming out of his ears 
I have an ancient opened pack of couscous in the cupboard. It has been re-sealed with the sticky down thing since opening. The best before date is Feb 2015 and there is nothing on the pack to say 'once opened use within x weeks', just says to store in a cool dark place, which it has been. Based on that and the fact that I use boiling water to prepare it, would you say it's OK to give to DS?
It's no big deal to buy a new pack obviously, but it's almost full and I don't like to waste food if it's perfectly good to eat (I wouldn't think twice about eating it myself).