Say you met an old flame at a weekend long event and you really hit it off again. They even go so far as to allude to spending the rest of your lives together. They told you from the start they were already seeing someone but made it sound like it wasn't very serious and they were starting to think that the other person was probably not on the same page as them. You email and share phone calls for months because you live across the country. The conversations are about starting a life together even to the point of determining where to buy property.
Your communication slows a few months due to both your schedules. Then one day you get an email from them saying they have contemplated things between the two of you and tell you the relationship with the other person (whom they say in the email they told you previously they were in love with... but you don't remember them ever saying this) has grown considerably and they have made a commitment to them. They continue to say they can only have one love in their life, are are glad to have had the opportunity to reconnect with you and see where you have both been and where you are both most likely headed and want to stay in contact as just a friend interested in what you are doing with your life.
Would you be able to take this person back again (romantically) if they contacted you months or even years later after this email saying things didn't end up working out with the other person?