I wrongly used `Marry off` thinking it was to get the person to marry and join

I had this nice dude who became an adult. Then a messenger appeared about a lady desperate to stay the night with her child. I let her work for a pay. She was super OP.

Soon enough she got 10k satisfaction and it was the first time I got a worker to reach it. Between the Join colony button and Marry off, I though "well, I want her to marry my guy" and quickly went for it.

English ain't my first language so I got pretty confused when I lost them three. My colony was small already as the grandparents died and now I lost one of the three grandchildren...

I had no clue at all that it was a possibility to have your colonist to leave the colony this way. I wish at least I could bring him back...