Up until the day Thor had been meant to be crowned King of Asgard, he and Loki had spent most of their days together in some capacity. Whether they were in cohorts or at odds, they were joined somehow. After that day, things had changed and for many years to come it'd been difficult for them. It was devastating knowing that when they'd finally found common ground and been on the same page again after so long having their relationship cracked, it was only for Loki to perish literally by Thanos' hand. Thor had still not dealt with that; he might never. Especially not when Loki was right there now, even if he wasn't the same one. It didn't matter, and that feeling seemed quite mutual.
He didn't tense or shy away from that wandering hand. Loki would find in his discovery that no, Thor wasn't dressed at all. Not a stitch of clothing covered his body. There didn't seem to be a reason to wear pajamas in a place like this. It'd just be something he'd have to clean and why would he bother with that if he didn't have to? It also was just a preference in the last span of several years for him to sleep that way.
Thor slid his hand out from under Loki's back only so he could run it down to his hip and thigh, squeezing as he pulled up, to hitch his leg around his waist. "By the gods, your mouth," he murmured, low and even a little needy. "I've never tasted sweeter." He traced Loki's upper lip with his tongue, before claiming his mouth again in a fiery kiss.