Cas wasn't offended by either the actions of Abra or Claire. In fact, considering Abra's usual disposition, it was very thoughtful of him, if ill-timed, but as soon as the situation was under control, he nodded to Claire and then turned back to Anna. He took her hands and squeezed them gently, knowing he was likely slightly flushed in the face and Anna was potentially on the verge tears. That was all confusing and an odd physical response to an emotional experience much less words themselves, but his thoughts shifted in one direction once the permission was given.
He tried to push the thought of being watched out of his head as he moved in and pressed his lips to hers gently. It was not as deep a kiss as he would have liked, but when it came to even that, he deemed it intimate.
As he pressed his forehead to hers briefly, he noticed the priest out of the corner of his eye eager for them to sign the register so he could close the ceremony, but he didn't care. All Cas could see was Anna. Dean and Cole could make their various remarks later - they would likely fall on deaf ears anyway. And if they did not, he suspected Abra would be sampling their drinks when they least expected it.