I think the decision to stay /go in a relationship is very personal, and it has a lot to do with the relationship that existed before drugs entered the picture (if the case), it has to do with the overall living situation and if one is generally happy and content living in their environment, and I think it has to do with what the relationship has evolved to be; and if it is acceptable for the other person.
Im here because my son’s use of powder cocaine, so it is a different dynamic for parent / child of course.
I would have to say that I am one of the people that does believe that my sons actions, ability to reason, make sound judgment calls has been effected by the use of the cocaine. He is 28 years old, and a functional addict. He has had enough time to show my husband and I just what type of person he is in regards to morals, ethics. Everything he has shown us has been positive and reinforced the success he has had in academics, personal relationships, and his career. But when he uses the cocaine, he becomes irrational. He makes bad decisions, he doesn’t think things through, he acts too quickly, he makes mistakes and doesn’t realize it, he thinks he is capable of more than what is possible, etc. All lead to trouble.
And cocaine like many other drugs triggers the pleasure centers of the brain; however it has been proven that cocaine in particular triggers the libido, and using is often tied to sexual acts; either in the flesh, or pornographic in nature. ( wont get more specific than that because ewwww… cant stand to think of my son in that way, but you can research it yourself).
But the act of forgiveness for cheating; while in a marriage; that is again I think a personal choice based on so many factors.
My heart goes out to you; while I can sense your anger right now, your pain is also coming through. I pray you find he answers for your own healing soon.