thx for info! i think i m playing the free with mod.I mean i know turn on/off the back option.This game handles relationships a bit differently than what you're likely thinking of -- the status of relationship isn't a numerical value that just goes up/down, but a combination of flags you set with individual choices.
The choices marked with heart indicate you want the relationship with character in question to be of romantic nature. The lust icon indicates you're thinking with your other head and they invoke sex-related activities without any deeper feelings behind it.