A lot of people keep in contact with old flames. However, I believe that old flames can be very dangerous to a relationship, simply because we keep romanticized notions of our old flames. We constantly compare new partners, the one we are currently in a relationship with, with our old ones. And a lot of times, what we remember are only good things and we focus on the good things. And somehow, when we engage in those negative comparisons, our current partners seem to not fare so well. And so, keeping in touch, justifying it by saying, "This is just friendship, nothing else," is always very dangerous because you never know at the moment the weakness, when those old romantic flames, those feelings come back and you'll be able to, then, succumb to temptation, something that's very hard to resist.