This is semi light hearted :)
Me having to share room with dc2 (20 months) or sticking him in with dc1 (12).
Ds1 doesn't one to share room with ds2. For a start he has lots of things in his room which ds1 makes a bee line for (think pc/xbox/tv) and it would be a nightmare to keep ds1 away from and they'd probably get broken at some point.
Ds2 also is still having his daytime nap and obviously goes to bed earlier than