If your having more kids let you husband have his way now and then Derek can be Ethan 's big brother. It worked for me !

Definitely Ethan..

go for derek....there are way way way too many ethans. its a nice name its to common....derek is still a cool name...

I like both, though ethan probably wins out in my mind today.

If you both really like your name and no neutral third option you both love appears you could simple wait until he arrives and see if hes an Ethan or a Derek. Sometimes it really helps to just wait and see who he is rather than fighting over it for the next few months if you cant agree or find a new name.