[James_Wilde]

Note added later: This suggestion is a good idea, but not feasible with present epub technology. See HarryT's comment lower down the page. Sorry. I opened my mouth before connecting my brain. The epub standard is so good, far better than, say, mobi, that I assumed it would cope automatically with columns. Now my original post:

Could be a problem since you don't know where the page breaks come. Why not use two columns? Many ebook readers can rotate the page through 90 degrees, so you read it in landscape mode. Short pages, but wider columns.

Another advantage is you can easily adjust so that the two texts keep in step. Translations are rarely exactly the same length! But an extra couple of carriage returns in one language or the other will do it.