Hey, I know that you don't consider SAKs as a possibility. I was like that too until a few years ago. But the bigger SAKs such as the
Victorinox 111mm series has a locking blade, along with a couple useful tools. Victorinox Soldier 08 will be a fine EDC, and not as intimidating as a Spyderco to non-knife people.
Victorinox One Hand Trekker is basically the same knife as Soldier 08, but with a less military look.
If you're interested, this time discuss with your parents, before you buy any SAKs or multitools.
And to think about it, Opinels are quite people friendly too, and they too have a locking system.
The Mercator K55K is also a people-friendly traditional knife with a lock.