Embarred about my size?

hey id like some advice on what to do. you see ive just recentley started seein a girl shes 16 and before she was going out with a 14 yr old. so i couldnt wait to get to y time expecting her to comment on how big i was and say how much smaller he ex was to me. but much to my humilation when it came to it i got " awww bless youve only got a baby dik" . so i straight away said maybe for my age but im biggest youve had, and again i was to be humilated more when she said " no he was about 1inch and a half bigger then you" im 18 so please what can i do or say