Levi wasn't particularly sentimental, that was true, but he had his moments and his quirks when it came to things to do with memories. This wasn't something he was going to try rushing -- sometimes Levi wasn't in a rush. He was willing to take his time to learn something correctly the first time when it mattered.
This mattered. Erwin mattered.
He let out a little huff of breath, not quite surprise or amusement but something gentler than all that and then shifted, sitting a little straighter so he could arch his back, press slow up into that kiss.
Which was -- actually kind of nice, once they'd found their footing. Levi hadn't exactly been worried it'd be wet or anything, but maybe it'd crossed his mind. But it wasn't really, it was just a good, gentle pressure that Levi decided he was eager to have more of. He got his fingers tangled up in Erwin's shirt to keep them on the same level even when he leaned back enough to take a breath before going in for seconds.