It really doesn't have to be large for us girls... actually I prefer a more modest sized member....
There a lots of positions out there to compensate for length and such....and as long as you both get off - who cares.... If a woman is going to have sex with you and you get far enough to show her yours....well regardless of size she not going to stop and say - I'm sorry it just isn't big enough - come on - who would do that!! She probably really likes you anyway for other reasons and it just doesn't matter after that. There probably as horny as you are - although they probably won't admit it... :)
And not to mention the Oral part of it - Well the bigger it is the harder it is to do.... So one of the pros of having a average penis is better head, probably the smaller you are the better it would be...... just something to think about. :p
Great works are performed, not by strength, but by perseverance.