Does an Uncircumcised Penis Require Special Handling?

The answer to your question, 'What should I do with his penis,' is, 'anything and everything you feel like doing.' Handle his penis the way you would any other model!

On a more serious note, I am sure that you are aware of the fact that sexual responses vary from person to person, which means that you need to adapt to each new sexual partner. Communicate with him and find out what pleases him most.

The issue isn't about how to work with his foreskin, it's simply about finding out what stimuli pleases him most. For example, some men like direct stimulation to the head of the penis, others don't. If a man prefers direct stimulation to the head of his penis, and he's not circumcised, then you might need to alter your technique and retract the foreskin in order to give him more direct stimulation.

Again, you need to find out what your partner likes and go from there.