[ He's hopping over the bar and mostly missing Kaworu's discomfort. It was a playful gesture on his part, mostly unconscious. To be honest, Kaworus said 'angel' and what Nick is seeing is 'cherubim'. After all, you'd think an angel would pick a tougher-looking body to walk around in. Besides that, Kaworu said he was raised... which means he's a kid. Kids can get a pat on the head every now and then.
When he takes the glass back, though, he kind of figures that it'd weirded the guy out. He's gotten pretty good with picking up emotional ticks over the years. Simple solution, just don't do it anymore. ]
Phoenix Wright. You can call me Nick if you want.
[ He refills the glass first before rummaging about for something of his own ]