Sounds like you and I are very similar in this respect. I've not had a bank account or credit card since 2013 so was very grateful to discover crypto in 2016. For the crypto/fiat process I have no choice but to use Sabrina's account, as I am blacklisted (and proud of it!). I set up a dedicated account for her with a UK bank called Revolut because they don't ask too many questions. Using uphold.com I am able to convert my crypto savings to spendable Euros in her account in just a few minutes.

I only recommend this route if you trust your partner ;)

Something worth noting however is that in the future we will be taxed on our crypto/fiat conversions. It is therefore preferable to spend it as crypto. Ideally as Monero or one of the other privacy coins!