I'd get a simple twin pram for the times when you will definately need one. Like when you have to go on long trips, or you know he is going to be tired, or going to the zoo etc. You don't need a very fancy, expensive one, just one that you can use easily and when you need to. My daughters are 15 months and 3 yrs 10 months now and I wish I had a double pram for some of my trips.