You already know the girls so even if you are looking at canned stuff you can ignore all of the openers etc. and tbh Phil has it straight you just need to take control and be natural aka best self and thats not asking her who lies more...
best thing before your party watch at least the couple of hours of RSD Blueprint decoded (find it on a torrent site) and it'll boost your self esteem.

Your putting a lot of pressure to perform for these 2 girls rather than making them perform for you - if you just relax and make sure you are the centre of the party and having fun then later you say "hey lets go get a drink somewhere quiet" they are going to want to go with and to quote Phil
massages etc. aren't for drunken house parties...