If Clint had reached out to make physical contact in some way, Bucky wouldn't have minded it. Though really, the other man's presence and humor were a comfort in of itself, and Bucky appreciated it a lot, especially right now. He was tired, most of the time, but right now he was especially tired of feeling the way he did right now. He was tired of being sad, of feeling lonely, and he needed a reminder that humor was still there and for fuck's sake, it was okay for him to laugh or at least to smirk. He would forever be grateful to Clint for that.
Hearing about the antics surrounding the cake did make Bucky wish he could've been there for it to see it in person so he could find even more humor in it because it would've been one of his memories, too, but given everything that happened he wouldn't have been in the right mental or emotional state to have enjoyed it at that point. It was better to hear about it now, when he had enough functionality in him to really respond to it, not just grunt and drink.
"Mm, up there," he said, when Natasha inquired about the glasses. He turned back to Clint, his lips still slanted upward in that little smirk. "We could've shared the fork," he said, and let that subtle attempt to flirt hang in the air because, well, Clint could do with it as he wanted. It could've been a flirtation, or it could've just been trying to keep things simple so it was one less utensil to wash. Whatever the other man wanted to do with it, he could.
He took a bite of the cake then and it was .. actually not bad. Different, as he'd expect alien cake to be, but it was good. Probably because it was the underside of a left testicle. "The left, it does make a difference," he added after swallowing. He needed to probably say more, something that didn't revolve around the conversation piece that was on the table but it was hard to know where to start. He didn't know what they knew, if they knew anything. Natasha knew he'd talked to Steve; he didn't know what Clint knew.
Bucky fiddled with the fork in his hand, kind of jabbing at the plate the cake was on before spearing another little section of it. "I'm sorry," he finally said. "I didn't keep my word to call, Natalia. I just... Sat down out there and lost track of the time." He ate the bite he'd scooped up. "Nothing left to do now but move forward." He wished it was as simple as that.