Then, moments later, Obi-Wan invites Luke on an overnight trip to a foreign planet without even checking with his legal guardian.
Then Obi-Wan caps off the trifecta of galactic inappropriateness by inviting this kid to a freaking dive bar. Presumably they deleted the scene wherein he buys Luke a carton of death sticks and the latest issue of Hutt-sler.
Now, we can forgive audiences for not thinking this was creepy at the time, either because of Alec Guinness' heartfelt performance or because their brains were so disco-addled that they couldn't think straight. But look at it now in the context of all the Star Wars movies, including the ones that felt like watching inexplicably racist paint drying. In the last of the prequel trilogy, Revenge Of The Sith, we see that Anakin Skywalker has turned so evil that he murders children.
And of course, he does so with the same lightsaber that Obi-Wan later gifts to Luke (while conveniently omitting that detail). It's even worse when you consider Luke's burgeoning powers. We've repeatedly seen that Jedi get Shining-like visions, sometimes from specific objects (and again, that holy crap there is an afterlife). Meaning that the lightsaber might have magically shown Luke all the terrible and cringeworthy things his dad did. Like social media will one day do for our kids.