I think I may be of assistance to you here. Your desire is quite natural and most women actually love bigger penis - at lease bigger than average.
I wish you supply vital information such as: Your bf penis size (is it up to 6 inches or less?), long but thin? Too small or micro size? Etc. Information like this will guide in providing tighter answers.
However, I will give you a general answer that will benefit you:
First, realize that your desire is in order. But do NOT tell him to his face. Why? Because PENIS Size has a lot to do with a man's Ego, Pride and Self-worth. Every man on planet earth is aware of his penis for that was the first part of our body we men became aware from childhood, just as women their breasts.
Secondly, ask yourself thoroughly, why do you really want bigger penis? Are you sure this isn't merely fancy? Or is your bf manhood big enough but lack solid, rock-hard ERECTION? Poor penile erection will make deep penetrate impossible! Or does he lack staying stamina?
Thirdly have you notice any worry or reduce excitement in him before, during and after sex intercourse? If so, then he too may be worrying about it himself. But believe me, whatever the real problem is your bf knows about it already.
Now how do you guide him to take action? This is actually simple to accomplish. Just as I'd explained above, it's necessary to determine the REAL problem so as appoint REAL solutions.
But for sake of explanation, let's both agree that it's absolutely small penis size. Here is what I suggest you do...
1) During intercourse, do not fake orgasm or act to make him feel happy. A lot of women do this because they fear their partners may feel sad if they don't moan, groan and howl. While this may be true, but it's like postponing ‘the evil day’ and enduring poor sexual lives. The truth is that, unknown to them, they're actually NOT helping the man at all.
2) Buy your bf men health magazines (old issues and new copies) for him. Most men health magazines are not all about male enhancement, but health generally. In some of the mags, such as A good one is “Men’s Health”, he will find articles about penis enlargement and men whose lives were changed for better after using penis enlargement extender.
Remember: Do not tell him to his face, "Read this mag, see that guy enlarged his penis, so do same now"
3) Do you browse the net together? If yes, then discreetly, surf towards male enhancement sites. I mean the once with lots of educative materials and success stories. Please be subtle and DISCREET so he'll take interest and look out for such sites himself. He may not even let you know, and that's okay.
Note: You may check out this resource: http://www.male-enhancement-tips-and-guide.com/tiny-penis.html
Now try these methods and see what happen. Meanwhile, do you know you can actually enjoy sex even with average size penis? You see, penis size, though important, is only a part of the whole game.
For example, a good knowledge of foreplay, nothing-sweet talk, finger-tipping, clitoris play, and ability to find the G-Spot of the woman is important. Penile penetration will only do the 'finishing' job.
I actually started my own journey and knowledge from that resource: http://www.male-enhancement-tips-and-guide.com/ By Akhree