I know it would be disruptive to switch up an established tag, but "multiple_fellatio"'s current state doesn't sit well with me. At least to my mind, it would be one person engaging in multiple acts of fellatio. It doesn't seem we have a tag for that, even.
So, in interest of displacing multiple_fellatio's wiki, I toss out team_fellatio (from the rather populated teamwork fellatio pairing) and group_fellatio (though this sounds more an orgy with 1:1 partners).
We may not find a more wieldy tag for "multiple persons fellating one penis" that what stands, but I hope others are less than satisfied with it.