How common is it for married couples to end up falling out of love and becoming roomates?
Pretty common among people that were virgins when they got married.
pit bulls bite
It happens more often than you think. People fall out of love. Partners change over time and sometimes those changes cause a rift in the relationship. Especially if the couple's bond was not strong enough to begin with. Some married people decide to just stay together rather than go through the trouble and expense of separation and divorce. While others, upon discovering that they are becoming distant, decide to seek out couple's therapy to try to fix the problems. Among the couples who decide to stay together, it isn't uncommon to see them sleeping in separate rooms, not communicating well, and choosing to pursue interests apart from one another. The best way to avoid problems later on in a marriage is to realize up front that marriage takes two people, its hard work and you have to be willing to do the heavy lifting to keep things fresh and interesting. Learning to to communicate whether things are good or bad, keeping date nights a priority even when/if children come about, making sexual intimacy a priority rather than a chore and being able to tell the other person exactly what you want/need. If you can do all that, then your marriage has a very good chance of succeeding.