Hi, the affair isn't usually shortlived: I agree we need to be careful of the 'stages' but Replay is described as lasting 2years + , and I think it is often longer. My h's affair lasted on and off 3 + years [broke up 'permanently' several times, including when they tried to move in together!!] I think he is still somewhat in contact with her, but it is more or less over. Remember it isn't a romance, it is an escape, a need, a fix, an addiction, and finally, often something they are scared to give up on because they have to start facing their demons ALONE.
Lots of debate here on whether they are truly reconnecting while OP is in the picture. I think the OP needs to be out of the picture if they are to complete their journey, and not simply come back to us with the journey part done, but there are a number of instances where spouse wavers between the OP and coming home. As HB says, lots of ways of doing this journey. Guidelines, not rules!