To go back to the original question, assuming you are
still within an area of England with more severe restrictions (an ever-changing list), and reading from your question that you are going to the house of one of you, then this is OK. You can meet up indoors with up to six people from (up to six) households.
You can even have your meal at the pub, as long as your group of (up to) six does not mingle in any way with any other group of (up to) 6 that happen to be there (even if some of that group are from your household.
Obviously, if you are outside of England, or within an area with more expansive rules/lockdown, the above does not apply.
Also, this is as of now (16:30 on 30/9/20). Give it five minutes, that may have changed
