Quick! To the Interlinear Bible!

OK, so Genesis 18:23 seems to use the same term as "wicked" which is sort of an antonym for righteous or godly. So it's both "bad, evil, naughty" and just "not our religion."

In chapter 19, the Angels are referred to as men, and the "to know them" is the literal term in Hebrew, so it's the standard euphemism.

Even looking at research into this (at a cursory level), it seems that there's no singular sin of which Sodom was a whole was guilty, just sort of blanket "wickedness" like society prior to the deluge. Not even everyone in Sodom as a town was "unrighteous" anyway - Yahweh murdered innocents just to get the other ones. There's not even much in the way of the sin being exclusive to sexual sin only, be that gay or anything else specifically. "Unnatural sex" is a term used once elsewhere, but that is also a term used for same-sex relations.

In the NT, Jude 1:7 refers to their sin as just fornication and being unchaste. So just horny AF. But that's a take from thousands of years after the fact.

It's really just that the inciting incident itself is about a crowd (we presume of men) demanding to rail 2 adult male strangers without their consent. Which, if you read the story is odd because they were planning to sleep outside in the square anyway before Lot gave them a place to stay. So it may simply have been the custom of Sodom (again, if we take this literally, which we should not) to fuck over strangers. That could easily be a sexual thing, it could also mean just rolling someone and stealing their stuff. Or maybe it was a mob of Amazons with ancient strapons planning to peg the strangers. Any of these are possible. But I'm also no expert here or scholar, so please read a real book about this. But usual sources don't seem to necessarily indicate pedophilia at all among the list of sins.