Phil blinked at the voices, because he recognized them, and once he realized that they were, in fact, coming from the people they were supposed to becoming from, it didn't take him long to figure out what was going on here.

The confusion on his face shifted to genuine surprise that then shifted briefly to suspicion and then to his usual sort of wry amusement. Mostly he was surprised by the fact that Clint was willing to share.

What he said, however was: "I can't say as anyone's tried to give me a heart attack for my birthday before. I appreciate it." And that was definitely an appreciative look he ran over both Steve and what he could see of Bucky, adding: "Though... I'm not quite sure how you expect this to go, I'm not quite as young as the rest of you. Relatively speaking, of course."