@ Author
We can see your brother devastated discovering her old flame relationship revived via brief's mentioned chat intercepts!
1. See as per Law an adulterous wife is entitled for maint. subject to her claimed grounds as in under civil and or criminal maint. laws of the land she claims before a Court. However if adultery gets proved then no alimony is given to her. There is a fine line of difference between maint. vis-a-vis alimony note that by scannign last 100 posts in family law forum.
2. The child is offcourse eligible for maint. from your brother whether adultery happened and or even divorce granted at the end of the day! However MCD is best option if both parties agrees to it. Still further if your bhabhi apologised and mending her ways then ask your brother to take deep breadth and take the family on vacation for revival of their marital relationships which makes the whole brief at the end of day manageable instead of getting their productive youthful years spent in various Courts.
3. In one of last months post I have made an attempt to bring out standards of proof required for both adultery / bigamy. Search that thread and see if your brothers case can sustain standard of proof to bring out adultery charges as alleged via your brief.
4. However the facts you mentioned hardly gives any concrete ground for divorce under either of these, as far adultery is concerned, mere chatting on net will not prove this unless the contents of the e-mail exchanged between the two shows s*xual relationship still exist between them!. There is a very old Hon'ble SC case law which may squarely fit here if this is what your brother can successfully prove reading down the saved chat intercepts.
5. See the facts of act of chatting on net with an ex-boyfriend by your bhabhi can be considered as her committing "mental cruelty" on your brother if she does so intentionally in order to bring mental harassment to your brother. Like continuing with chatting with her ex flame for days / months together.
6. However if once she is informed about your brother having knowledge about her internet activity with her ex-boyfriend and she stops her chat activities then your brother cannot make this as ground under 'cruelty' for seeking divorce decree. In my opinion he will fail miserably in Court.
7. Lastly if your bhabhi after being told of your brothers objections for all her internet activities and she still continues then definitely this can be made as ground of 'cruelty' and there pops a divorce decree on ground of probability of adultry committed by your bhabhi.
In a husband - wife relationship if they are sharing a common PC / Laptop / Tablet then such consents are not required and or made out of the nature of hacking as asked in your last para doubt before us. It can always be argued as to be a “devastating chanced heart breaking discovery" by a god fearing - down to earth simple Husband my lord J but charges still remains of her adultery so let the case proceed so that I am able to prove to Court kar key……......