When one posseses the inability to decide on one romatic interest- in this case, of the male variety. Includes frequently changing one's mind about which boy one wants to be with.
1. Katie: OMG. I just got a text from Matt, he is going to meet me at the bar tomorrow night.
Cailee: Wait, I thought you had a date with Craig, that you were super excited about.
Katie: No, I think I like Matt- he’s witty.
Cailee: ugh… you are so boy-polar!
2. Katie is boypolar, last night she liked Craig, this morning she woke up with Matt.