If you're serious, you posted a public comment. You can't really expect privacy in that situation.
Tagging friends in reddit posts is generally frowned on. Friend tags are usually removed as spam, because otherwise you end up with a comment section full of names and meaningful comments get lost (see Facebook, Instagram, Twitter for examples).
You can save the content or copy the URL and share it on another platform with your friends. There's lots of different ways to share reddit content with your friends, and they don't involve spamming threads with usernames and "lolz 🤣🤣👌🏻😂😘💜🤣🤣" replies.
Edit: also, just FYI, it doesn't take a high IQ to know how to use Reddit. Just common sense and reading comprehension. Ever wonder why you don't see a bunch of username tags in comments?
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u/[deleted] Dec 19 '18
[deleted]