Illicit relationship of wife (Christian) & divorce

My home Wi Fi was monitored for my 2 teenage daughters, however when checked it showed that my wife aged 48 was having an illicit affair with my daughter's boyfriend aged 25. We know this boy since 5 years & he broke up with my daughter since 1 year & started a relationship with my wife. The Wi Fi capture showed that they have been discussing about sex & he claims that its been some time since they did it, they also exchange love greetings & kisses, and they also have plans for him to sneek into her bedroom one night.This was a chat conversation & when confronted both of them accepted it & claim as ONLY flirting. My wife sleeps & wakes up with mobile chat. How good is my evidence of TCP chat files captured which show time stamp, ISP name & tel number & and their verbal acceptance, for a divorce. Also I have a letter copy of their affair after she was caught, Initially my wife accepted as her fault & depression, now since 4 months she has gone to her parents place with the 2 kids & does not want to come back. She says that she has been suffering with the 23 years marriage. But wants one house in both our names to be sold & given her share, this house was purchased by me through NRE joint account & I cleared the loan in full. A second house I bought in her name through a loan given by her sibling & cleared by me in 4 years with no loan papers she says she will sell that, however she had no source of income. How good is my chances for contested divorce for illicit affair, or should I go for mutual consent.