Who's name will the kids take?

Hey there! So when my husband and I got married, I decided not to drop my last name. Instead just hyphenating Foxx-Jagr. But we are having twins in August...but I have a question...what last name will they take? I know this may sound really silly question, but we are a bit confused about the way things work here. (I'm Canadian and he is from the Czech. haha)