Making out with some one of the same sex for it's ironic value or to create an ironic situation.
n.b. Though the term is most often used in hipster cirlces to explain away the awkward sex triangles that sometimes occur.
Len: OMGOD Ryan, you and Jordan were just making out.
Ryan: relax Len, it's cool - we were doing it Bironically.
Len: uh, well, i'm still telling your girlfriend
Ryan: Birony !