A Y-splitter for two headphones wouldn't work (well) due to signal degradation because of electronic issues. Also, what if you'd like 3 people to see the movie ? If you think that's how you'll be watching movies in the near future, I'd try something like this -
http://www.behringer.com/EN/Products/HA400.aspxIt has quarter-inch input and outputs, but once that's addressed by adding 5 1\4" > 1\8" adapters (should cost about $10), you'll be able to connect up to 4 'phones and control the volume level for each. I've heard it only once at a small studio, quite briefly though - it does it job quite well ... I wouldn't use it with hi-end and for audiophile listening of course, but for your purpose it should be great.
Other than that, I'd see if Cesar Millan could help.