Dr. Lindsey Doe is a sexologist who, for many years, ran the YouTube channel Sexplanations, one of the earliest sex-ed focused channels on YouTube. She left with little warning about a year ago but she's back!
This is really exciting for me, personally, because Sexplanations is the channel that got me interested in sex and relationships as an academic field and I still link people to her videos on a semi-regular basis.
I think she's the gold standard of online sex-ed, and I'm glad she's back.