EXPAT FAQ
https://www.easyexpat.com/en/faq.htm
US citizens: I've married a UK citizen in UK, how do I fill my US Tax form?
You need to file a Married Filing Separate return. MFS filers cannot file a 1040EZ but can file 1040A instead. You will not have to include your partner's income, and deductions in your return.
You can file this form once you move to the UK as well (unless of course you start working in which case you have to file a 1040 (with the relevant schedules) and forms 2555 and 1116).
However the good news is that the income your will earn in UK is subject to the foreign earned income exclusion (calculated on form 2555) and also you can claim a credit on your US return for any UK taxes paid (calculated on form 1116). This way you will avoid paying tax twice on the same income.