Well
Flint xo,
You both followed the script that was given to you. The scene needed some kissing, a reach-around, or neck nuzzling, or some nipple play with fingers or tongue, or something...to liven things up. There's only so much that can be done (for even the most experienced of models) with a script that has one guy seated and being serviced the whole time. When the most active person on the set changes position only once...from giving a BJ seated to giving a BJ/handjob kneeling...the timing and pacing of the scene suffers. I'm sure your guys' next scenes will be better.