As found and posted by TMF member Travis:
'David Boreanaz quotes from Orlando Sentinel, when asked about working with Charisma Carpenter:
"She's great. I can honestly say that she is the most talented leading lady I have ever worked with. We just finished shooting the ballet episode, and we sort of had to do a love scene together. It was pretty funny, because Charisma is extremely ticklish, especially on her stomach, so when I had to go down, kind of made her laugh. I would start laughing, and then Joss would get so upset and start
telling us that if we don't get this done he will fire us both, but she kept laughing, so finally I just said screw it and gave her a raspberry, right there. We took a break after that because both of us couldn't stop laughing."