Hmmm... I think if I was working on a guy for 20 minutes with the objective to bring him to orgasm and it wasn't happening I might try a little COMMUNICATION. Actually, I'm pretty lazy so after about 10 minutes I would probably be like "I'm going to take a break. Why don't you just show me how you do it and I'll watch." Of course, I'm also greedy so I might just take a break and signal "Me again."
"Tell me, what is it you plan to do with your one wild and precious life?" - Mary Oliver