Why not? You want to save your marriage, right? Then put your pride and who aside and give her more. Be the man only a fool would leave. A selfless one.
This. I think we get too hung up on what is fair or not fair, rather than on what is going to fix the relationship. I just posted this on someone else's thread, but one of the biggest reasons I am in the process of getting D is because of an attitude like this. H had an A, and I felt justified about anything I wanted to say or demand of him afterwards (insults, lack of trust, constant reassurance, explanations, extreme accountability) because "it was his fault." Wrong. He made the choice to have an A, but we both contributed to the environment in our marriage that made him vulnerable to that temptation. If you want to save your M, now is not the time to focus on what's fair. There is a reason your M is at this point, and it is probably not the sole fault of any one individual.
When H and I got married many years ago, my FIL gave me a bit of advice that has always stuck with me through the years. He said, people always say marriage is 50/50, but it isn't. Sometimes it's 70/30, or 10/90. Sometimes you're doing all the work, but the next time, it will be your spouse who is carrying the heavier load. Since you are the one who wants to save your M, right now is your time to carry that load. Keeping score will only get you a D.