I don't think you're crazy for not breaking up with him. It is completely up to you whether you accept his apology or not. If you believe that he's sincere then it should not matter what other people think.
There are some men and women who will always have a tendency to philander. However, there are others who can legitimately be a victim of circumstance; people who would not normally engage in sexual activities outside of a a relationship, but find themselves in a predicament where it is extremely difficult to back out of. Like if a guy is drunk and another woman aggressively seduces him. Or a woman who is in extreme distress and is surreptitiously consoled by someone who wants to screw her brains out and will do anything to make it happen.
Relationships are rarely black and white because people come in a variety of personalities with different backgrounds and needs.
You will know what is right for you and don't let the opinions of others dissuade you.
There are some men and women who will always have a tendency to philander. However, there are others who can legitimately be a victim of circumstance; people who would not normally engage in sexual activities outside of a a relationship, but find themselves in a predicament where it is extremely difficult to back out of. Like if a guy is drunk and another woman aggressively seduces him. Or a woman who is in extreme distress and is surreptitiously consoled by someone who wants to screw her brains out and will do anything to make it happen.
Relationships are rarely black and white because people come in a variety of personalities with different backgrounds and needs.
You will know what is right for you and don't let the opinions of others dissuade you.