Tile/grout/caulk on tub question for the experts here.

[TNDemo]

Mr. TNDemo and I are rehabbing the master bath. Tore out the old shower stall and closet and put in a Jacuzzi. Jacuzzi is in and working but room had bare wall studs and subflooring showing until this weekend, which gave it that Green Acres feel. Kept waiting on Alf and Ralph to walk in. Anyway, got to work this weekend and got the floor put down and now he is putting up the necessary stuff for the shower wall (put a shower head on each end of the tub so you don't have to turn around to get wet or maybe have company in your shower) and I will do the tiling. What we are wondering about is the where the tile ends at the top of the tub. Do we grout that also or just caulk? It seems like it would be a problem with grout since the tub will shift with the weight of the water. There must be an easy answer for this since millions of tub have tile around them. What's the best way?