Love after marriage

What are the roles of love after marriage? Does love after marriage is allowed only between husband wives or they both can pursue love with others? It is believed wrong to have love affairs after marriage. But men are men and it is very difficult to put mind in single direction. Therefore many times come in life when we have no prospect but to attract towards the other sex. Some time these attractions are so forceful that they even break our old relation. Now here what is right or wrong? All this is becoming more complex with the globe becoming a more complex place to live. People are coming out of their homes more frequently to interact with other people, thus increasing the possibilities of attraction towards other person. All this may be signing a change in the way of our lifestyle and believe towards relation. However we have no choice but to wait and watch the action.