Disadvantages:
unrealistic expectations leading to unfulfilled fantasies....leading to breakups that cause people to hate each other when all that could have been avoided if people would enter into healthier relationships with realistic hopes and goals.
loosing ones sense of "self", loosing your Independence and freedom.
Being treated like you are someones property.
The inevitable path/goal of "long term commitment/ marriage"
Advantages:
someone to talk to, spend quality time with.