My WH cheated multiple times on the GF he had before he married me (and the excuse he took was that she cheated on had to be someone else's fault, of course.
I knew it and still went ahead and married him. Guess what...he kept up his habit.
Those cheaters and liars do not change unless something major rocks their life. Otherwise they see cheating and lying as a way of life. They also love to point fingers and attribute their filty behaviour to others, namely their spouse.
Given all of the above, you will be sparing yourself very much pain and anguish. By the way, serial cheaters do not love anybody but themselves (and even that could be debated.)