Shemira for Chasan and Kallah after wedding

What are the laws of Shemirah for a Chasan and Kallah after the wedding? Is it really an obligation to be careful? Cna the Chasan and Kallah guard each other when they are together? What about going to Shul if a Shomer is not available? Who is valid as a Shomer-a child, gentile? 

To read the full article on this subject see here on our website, or our Sefer "Topics in Practical Halacha" Volume 1 E.H. Halacha 15