No, results can't be shown for two people on one page.
You could set up a second account and use that.
But since you're eating basically the same things anyway, I'd just use one tracker and "just know" that the one getting slightly more portions is getting bigger numbers. If you want to track things he eats on your tracker that you don't, just so there is a record he ate that (without numbers) just add a manual food item with 0 values for everything. eg "Choc bar - Steven". Then your tracker will show that he ate that, without your values being affected.
Deb, in New Zealand