How can this be regarded as adultery if you dont see them, talk about haram things or are tempted to meet them and do haram?
Answer
If there is no need to talk to the opposite gender who are non-Mahrams (not prohibited in marriage), then that is a sin.
Shari?ah strongly advocates separation and segregation of sexes. The evils of intermingling of sexes and free communication between them are well known. In brief, it is death to a pure and clean heart and mind. It is death to spirituality.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai