Can I get divorce

Sir my name is vicky from jammu working in indian navy and residing with my wife in andra pradesh For 15 days i was gone at sea for patroling in east coast of india. My wife called her boy frnd to my home and he stayed with my wife for 9-10 days.Actually he is my wife's cousion Mama( brother of my mother - in - law).His age is 23 and he is unmarried. My wife age is 20. My wife not informed me about the presence of her mama.I came to know from my neughbours that your wife's mama had come in your absence. Before i was going to sea my wife have 2 day of mensuration peroid .After coming next 15 days i dont have any touch to my wife due to dispute between us. Now i dont have any physical touch to my wife since last 40 days but my wife is pregnent. Now sir i want your suggestion that I have witness for presence of her mama to my residence I have a proof that i m out of station for that duration. I have pregenency report of my wife. Now sir what i can do. Can i proved the adultry of my wife. Can i get divorce easily sir plz suggest me Thanks