First of all, it will never be the same as you have the knowledge of what else is out there and because you know you have cheated. Why did you disconnect from your partner in the first place? How have you and your partner changed since you got together so young? The twenties are an important part of finding out who you are and what fits, so to speak.

I hope you find some clarity in this situation, but realize it will NEVER be the same with your first partner.

Your new partner is with you knowing about your current relationship. Would you be okay knowing that about him, as he might do it again or leave you because he only dates women in relationships? He was there for you in a difficult time and you allowed him to comfort you in a way your partner used to. In essence, you replaced one with the other. Now that your first partner is "the way he used to be" you are ready to discard him.

One is love and one is infatuation. Which one?