Paige did kiss Alex in Free Falling pt 2 (the couch at Alex's), she spent the night there. She called it a 'goodnight kiss' Alex did have a girlfriend after all. Alex kissed Paige in Love My Way and told her she loved her. Paige kissed Alex in Don't you Want Me pt 1 after telling Alex she was a free woman. Alex got mad because she felt Paige was playing with her feelings. In Don't You Want Me part 2, Paige asked Alex to be her 'sweetheart' and Alex kissed her. There were issues, they sort of broke up and got back together at the end. That's where all the season 6 kisses come from.