Las Vegas with Friends versus with Family?

[modelguyy]

I'm turning 21 next month along with my best friend. So my friends decided for both our 21 b-day's we all go to vegas. If i go with friends i party hardy. Then my parents decided they want to take me to vegas along with the whole family. so that means a lot of sight seeing and no partying. I really want to go with friends because first time to vegas and 21 i know a lot of partying a lot of girls a lot of drinking and sex and strip clubs and night clubs and you name it. But with family that won't happen. More like shows at night and a LITTLE gambling and a LOT of sight seeing. I prefer with friends but my parents say they are already ordering for airline tickets. I really want to go with friends but don't want to hurt my parents by saying no to them. How do i get out of this, how to fix this problem? how to go with friends without hurting my parents feelings?
some of you may say you can always go with friends later. But you only turn 21 once and celebrate b-day there once.