Guy's Behavior

What does it mean when a guy keeps messaging me TFTI on Snapchat?

I added a guy I'd been working with for two or so years at school on Snapchat the day I quit, and sometimes he messages me "tfti" on my Snapchat stories. My friend told me she does it for sometimes, and means nothing of it but like... really? Didn't the tfti meme die already?

I get confused because he says he's down to hang out but he never asks me out even though we both mutually like to drink and have discussed it offhandedly. He also saved my Snapchat message where I said we could literally go eat out anytime, so I figured it meant he cared like at least 1%?

He has also flirted with me apparently and I didn't have a clue until other people reviewed my texts and told me he was referring to sex lol.
One example being that I asked him how tell he was b/c I was talking to my friend about him and she had asked, and I figured the best way to find out was just to be direct and ask him. He responded with "I'm tall enough *that one sideway smirking emoji*" before actually telling me his height. ((I know I'm so dumb for not realizing but I was eating food and honestly I was too immersed in that to really use my brain.))

Anyway, I gathered he's not interested in me and he's just keeping me around to boost his ego when I give him attention but like... why lol. Does anyone else do this and why?
What does it mean when a guy keeps messaging me TFTI on Snapchat?
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