I'll take it another step farther. In the congregation I grew up in, it was unusual for brothers and sisters to even work out in service together, even if married. The brothers always went in car groups of brothers, and the sisters likewise. There was a prominent elder and a pioneer that were both married to other people decades ago that were hooking up while out in service and that congregation was paranoid like no other. I don't think I ever even spoke to any of the young sisters in our hall until I was in my late teens. It just didn't happen. We were all kept apart.
How great would it have been if a same sex partnership developed out of the bros on bros car groups, or the girls on girls ones? Those people would have insisted on working solo at every door forevermore.
I pioneered out of high school and worked alone many times because the sisters didn't want to work with me. It was one long, awful year. One time I did give a ride to an elderly sister to her house just a few blocks from the hall for some reason (maybe her car wouldn't start or something). I'm sure it would have been scandalous if we were caught together. I was maybe 18, she was in her seventies, so anything could have happened.