Lol. I was so naive, you wouldn’t believe it. They were from England where there is an actual queen (Elizabeth). I drew no sexual conclusions from the name (just as it never occurred to me to consider The Beatles insects or entomologists).
I’m not sure they had recorded Killer Queen at the time they were opening for ELO. Didn’t that tune come a bit later?
That's a good question. "Killer Queen" was from their 1974 album "Sheer Heart Attack" and charted the same year. I'm not sure when Queen toured with ELO - do you remember?