she left her betrothed to run off with a married man - as a result of not telling anyone, a war is started, her father is burned alive, her one brother is killed, and the other (Ned) is very nearly killed - thousands die including her love, Rhaegar, and his family is overthrown and murdered - then not only does she give her child to Ned and asks him to keep a terribly secret that causes marital strain with Cat, she also has the nerve to name him after Rhaegar's other son that was killed by The Mountain (he might have helped name Jon/Aegon as well, but still) - all of that, just because she was thirsty
to be fair, she never asked to marry robert, it was an arranged marriage.