How can I convince my bf that his member size doesnt matter to me?

Unfortunately, he will probably always be a little self conscious about it. Just tell him how good he feels inside of you, moan it in his ear when you get close to orgasm.

We shouldn't arm ourself for war, arms are for hugging

Give his penis a really butch nickname. Like 'Frank' or something.

Sleep naked!

I used to have a boyfriend who had the exact same problem with himself. Sometimes he didn't even want to have those exciting sexual encounters where you have the chance to get caught because he was so insecure about his thing.

I guess all you can do now is to find out ways to enjoy sex better. Try out new techniques that feel mindblowing for the both of you. Because let's face it, men are competitive and slightly insecure by nature. Somebody was right when s/he pointed out that you have to make him feel that he is still a huge stud in spite of it. Go girl! I wonder when I'll get to try that out with my next prospective boyfriend.

Don't talk about it's size or anything. Don't even make it a topic of conversation. Look confused if he brings it and say, yah, whatever.

Then, when you are in bed, worship the darn thing. Love it, kiss it, lick it like it is the most amazing thing ever. Look at it and check him out and perv out on him when he is naked. Tell him how hot is 'body' is. When you are doing it, be enthusiastic. Text/IM him and tell him how much you want to feel him inside you RIGHT NOW.

Talking about it won't ease his insecurities, showing him how much you adore and worship his cock will.

I know, I'm a little self conscious about my breasts, and the men who act like that get me over it.