Hillary Clinton and Barack Obama appeared together Thursday night, marking their first joint event since Clinton dropped out of the race for the Democratic presidential nomination. The event, a meeting with about 150 of Clinton's top donors, was meant to encourage party unity -- and fundraising, of course -- but judging from some reports, there might still be some work to do.

ABC News' Kate Snow has details from some Clinton supporters who said there was palpable tension during the meeting, and that some of Obama's attempts to reach out fell flat. One unnamed "major Clinton donor" told Snow, "This felt like when your mom forces you to go visit your Aunt Ida and she has to pinch your cheeks and you're sitting there in an uncomfortable suit and you can't wait to leave." Another of Snow's sources said "[you] could cut the air with a knife" because of the tension, and that attendees were joking that the atmosphere was like "an Irish wake."

There were some awkward attempts made by Clinton supporters to smooth things over with Obama. Lanny Davis, a top Clinton surrogate unpopular in liberal circles, reportedly introduced himself to Obama, who responded, "I know who you are." According to the Atlantic's Marc Ambinder, Davis then said to Obama, "I don't want you to take out of context what I said during the campaign."

Ambinder also reports on some of the questions Clinton supporters asked of Obama after the press had left. One asked Obama whether he'd make Clinton his running mate. After that question, Ambinder says, "Even Sen. Clinton looked uncomfortable, gesturing to Obama to move on, which he did."

But it wasn't all tension. According to a pool report written by the Washington Post's Shailagh Murray, when Clinton -- with Obama standing by her side -- said, "We have to make it a priority in our lives to elect Barack Obama the next president of the United States," she got "sustained applause," and there were other, similar moments when Clinton supporters cheered the idea that Democrats must win back the White House. And Obama's promise to help Clinton collect money to pay off her campaign's debt got a standing ovation, Murray says.

As part of that promise, Obama himself has just donated $2,300, the maximum allowable by law, to Clinton's campaign. His wife, Michelle, did the same.

The two will make their first public appearance together in Unity, N.H., on Friday.