Yes, it was stupid.
The reason I did it was I originally didn't see award availabilty for LHR-ARN, and only realized it was available when I booked for my gf right afterwards, noticing GRU-LHR-ARN was a bit cheaper than separate bookings.
And I wanted to use my Gold status to link the bookings, so we could select seats for free on BA, so we needed to have the same itinerary...