ok then well firstly im not that thrilled about the bring a mate idea but the at the same time its good that your putting yourself out there. now im not so sure how to approach this but i feel a good way to do this is to approach this as a simple 3 set . focus on your friend and hers and neg her occasionally.
attempt to build up kino and then after try to leave your mate and hers . this is gona be very tough but if you build up enough attraction throughout the date it can be done.
if this isnt possible simply try to isolate . take her hand and say " come keep me company , i wana get some popcorn " or something . you get the idea.
once youve isolated as long as there is some sexual attention i suggest trying for the k-close.
in the cinema you have to, this is imperative , you must sit next to her.
possibly ........... yourmate,her mate,you,her. hopefully this is the best way to position but you must sit next to her.
and yes taking her to a horror is a great idea

. hopefully shell cling to you for " protection " haha and this will give you a chance to build up some more kino. as a side note this is a good chance to neg. also if she holding on to you , make sure to lift her head and make very strong eye contact. build up that sexual tension !!!!!!
i hope ive helped mate and be sure to let me know how it goes.
good luck
