If you read my post, you’ll see I didn’t say that.
I didn’t say you said that, I said do you really think that the term adultery wasn’t covering fornication too?
The Ten Commandments are shorthand for Leviticus. Adultery was a blanket term that was understood to also cover sexual sins of married or unmarried people. Just like “honor thy father and mother” didn’t go into all the detail that that phrase entails.
And if you want shorter shorthand, Jesus’ compaction of the 10 Commandments into the 2: Love the Lord Your God with all your heart, mind and soul (the first four): and Love Your Neighbor as Yourself (the last 6).