Many signs shout that This has to End. I'll give u few:
He/She doesn't call you though they promise.
He/She ignores to catch up with you.
There is no more compatibility between you. eg If you're a gypsy and He/She is a city admirer.
He/She avoids talking the future
He/She is not interested for any close relations. e.g. having sex.
He/She stays late in office or stays more with friends but not you.