honestly, i could see how this would be a difficult choice.  on one hand, going to spain for a week with your girlfriend will be incredible and probably something you'll remember for your entire life, but if you don't get to see a lot of your family and friends (mostly family) very often, then having a party as an excuse to get them all together and see them all at once is also pretty cool; it'd almost be like a reunion.  i never see my extended family, and i don't mind because they're mostly awful, but if i liked them and have friends i got to see infrequently, i'd be tempted to go for the giant party.

if you don't go to spain you are a retard

you can randomly have a drinking party whenever you want. and if you're a functioning human being, it'll get really boring within a few years

Yes.

Definitely go to Spain, there will be drinks in Spain, plus alone time with your girl. You should be happy to have the chance to see Spain or any other "exotic" locale at a pretty young age. Also, if you want you could make a smaller sending off party with your friends and family before you leave for Spain. That way you get the best of both worlds. =D

Been to spain, the place is lovely. You should go, it'll be quite memorable.