One of the questions by Mr. V S Rajam was
What is told/informed to a bride and groom during the wedding ceremony about “marital fidelity?”
 
------ There are several different occasions during the Vedic marriage when bride and bride groom are made to take oath.
 
One of the most well known, popular oft-quoted is :
 
Bride's father : dharma cha Arthe cha kame chaishaa naaticharitavyaa
 
Bridegroom:
 
Naaticharaami.
 
For the remaining such oaths taken by bride and bridegroom during the marriage ritual, you might want to refer to one of the huge number of publications of Vivaha mantras abundantly available on and offline. 


--
Prof.Nagaraj Paturi
Hyderabad-500044