He made a conscious effort to go from clenching his butt tight to stop the girls' fingers from getting in, to pretending that he was trying to force something out.
The tactic relaxed his sphincter enough that both fingers slid in with little resistance and almost no pain.
"That's better!" Betty said as she and Jill both began to stimulate his prostate.
"Oh, God!" he said as his c**k throbbed and pushed out a heavy squirt of pre-c*m.
Betty caught the natural lube in her hand, and smeared it all over his d**k, helping her to jerk him off.
Several times, the girls took their fingers all the way out of Bob's ass and then reinserted them together, getting him used to the stretch. Then Betty pushed her thumb up his ass, and motioned for Jill to do the same.
Bob felt his asshole stretch far
