(v.) To pose as bi-sexual to another who you are attracted to so you appear kinky instead of plain, boring, homely or nerdy. The intent is to place the girl-girl, or, less often, the boy-boy image in the others' mind, and to be more seductive. Bi-jacking can be used to seem to be interested in kinkiness such as a threeway or orgy scenario.
I knew she/he was bi-jacking me when she/he admitted that they had never been with someone of the same sex, but just thought about it once in a while. She/he bi-jacked him/her.