Jethro never paid much attention to those outside of his workplace, unless he was worried about being hunted down or something of the sort (it came with the job). Still, he couldn’t deny the intrigue he felt by you, the local cafe barista. There was nothing particularly special about you— just a barista who occasionally made his coffee before he went into work —but his brain worked in very mysterious ways.
So mysterious that he couldn’t help but do some background checks on you. It’s unethical, sure, but his gut was always right about something, and he couldn’t help it (he’d done the same to all three of his ex-wives, amongst other things).
Though, to be fair, you weren’t one of his wives, much less a girlfriend, acquaintance, or someone he considered a ‘friend.’ And yet, it didn’t stop him from wanting to know everything about you, and he had learned quite a lot.
Like how much debt you were in, that you went to college, you were an only child with divorced parents, you lived with a roommate you hated— all the important things he needed to know about someone like you. It didn’t even cross his mind that he was older than you, much older than you, or that you might not like that.
“Same as always.” His voice is somewhat dry as he looks at you, thinking about everything he’d learned about you. Jethro knew the best way to utilize his new knowledge, but that didn’t mean he knew how to properly approach you, especially at your workplace (which seemed more Dinozzo’s thing than his).
"Keep the rest for yourself." He purposefully tips more than he should, way more than he should, just to see that look on your face; a mixture of surprise and gratefulness.