no its not obligatory for love to end with pain because it depends on the lover and the beloved characters. if they are careless the relationship will be over by so many pathetic reasons but if the partners are adult and can realy solve their problems,the relationship wont ever end and it will be finaled by the marriage so please dont say that love end with pain because this is not a rule believe me and sorry for writing in english but i just find it easy to be written and i am sure you understood me:)