Its because you have to prove adultery (unless they will admit it) where as you could say unreasonable behaviour of such and such which leads you to believe they committed adultery or are having a relationship which is intolerable to you. In this second option you only have to convince a judge that your belief and feeelings are reasonable rather than prove anything.
Both mid 30s, 2 young kids BD 7sep14 XW moved on long ago, now living with OM1 D paperwork in progress
