Okay, I've been thinking about his a couple hours and I have a somewhat honourable (I think) plan.
Much as I'd love to ravish Tara all day (week/month/year), I'm an adult and there are things to do.
First, wake up and tell Tara a simple version of the truth - can't do the spell, bikers to worry about. More details later.
Then, assemble the scoobies, tell them that current plans are off and that the bikers must be dealt wtih. Keep Spike alive for now for muscle; call the LA folks and see who's willing to help and who can get there by late evening.
Have a very cold welcome for the biker demons upon arrival. Stage things just right so that it seems that the Slayer, alive and well, knew they were coming and mopped the floor with them. That takes care of the Bot's cover.
Once that's done, tell everyone that you know Buffy's in heaven and that she should stay there. Go to prison and visit Faith, forgive her, tell her the sitch and arrange her release/escape as required. Have Spike leave town at stake-point. Offer little mercy.
Catch the nerds as they leave the bank robbery, red-handed.
Go home and ravish Tara for the rest of the week. By then, I'd have EARNED it.
