How do you convince your boyfriend to perform cunnilingus?

The best way is to talk to him. Ask if he's ever done it. Ask him to do it for you. If you let him finger you, that's probably a good time to ask. Let him do it until you both are really into it and then ask him. It may not work for him, but I know when I was young, or even at my age now, there are few things hotter that a girl asking me to do something to her during sex.

He may be nervous because he doesn't know what to do. If that's the case, help him. Tell him what to do. The easiest way to a great sexual relationship is to be open with your partner. Talk to each other and let him know when something feels good or bad. How much will you enjoy it if he finally does it and completely misses your "sweet spot"?

Another way is to watch a porn or look at a magazine together. If you see something you like, tell him that you'd like to try that.

Also, if you are going to ask him to do that, you should be prepared to return the favor if you don't already. It's only fair.