Am I Wrong?

I once asked the question to a friend of mine "Is it wrong to be exclusive with someone and think of another?" Of course he immediately thought i was thinking about him. NOT ! Now don't get me wrong I'm not trying to jump in bed with anyone else but there are those thoughts sometimes lingering around "What if this, what if that." I am in a happy relationship with a wonderful man, so why don't i fell happy at all times? Why do i have to pick and choose the day and times to be truly happy or to complain about what would "possibly make me happy" I don't know maybe i want my cake and eat it too. I am kind of fond of cake too. . . LOL