Native speaker of English & Spanish. Born in the US, technically, but we moved because of some job my dad had, I think.
He decided to stay in South America, and when I learned about certain things via friends, school, and the Internet, they happened to be in Spanish.
My parents, who I spoke English and Spanish with, didn’t really teach me certain adult stuff, so I learned through literature and school assignments (but also TV).
(So sexual topics and topics related to drugs I learned in Spanish)
I’d say I have a much bigger vocabulary in English than Norwegian. It is ultimately only natural to end up with a bigger vocabulary in one language than another, though: we are after all not equally proficient with both hands, so why should those of us raised with two languages be equally proficient in both?
Still, when I actually live in Norway, I feel like I really should have a bigger vocabulary in Norwegian.