There's been some talk about Christine McVie reuniting with Fleetwood Mac in concert . . . and now, it's officially happening. Somewhat.

Stevie Nicks says Christine has agreed to join them for a song at two shows during their upcoming European tour. She said, "She's going to come [up] and do a song. I think it'll probably be 'Don't Stop'.

"I don't know, but she's coming to Ireland to rehearse with us."  It's unclear which shows Christine will be at.  The tour begins in Dublin, Ireland on Friday...followed by three shows in London.

Since she's going to be rehearsing with them in Ireland, it's probably likely that she'll appear at one of the shows in Dublin. Christine hasn't been a part of Fleetwood Mac since 1998, mostly due to her fear of flying.