My sisters boyfriend cheats on her and uses the following excuse?

The logical thing would be to leave but she is the only one that can make that decision. He is cheating and blaming her for his infidelity...that is ridiculous.

You said that she confronts him. Then what? He obviously knows she isn't going to do anything other than confront him, there are no consequences for his actions.

What is she to do?

Nothing.

She is not married! She doesn't want to be married. The only reason she got together with this guy was for the free sex. Because there is no vow, no promise, no covenant of any kind, by her own actions she told this guy the only thing she really wants is sex.

This is ALL it can be about!

Her own actions told this guy that she doesn't care about sex INSIDE of marriage. All she does care about is the sex. And wow! he fully AGREES with this morality!

Why do you think he's doing what he's doing?

Because she told him that sex anywhere with anybody at any time is OKAY with her! She proving it in her own life!

and p.s. - it's kinda hard to cheat when there are no RULES to govern the "relationship". (he's not cheating!) He's not cheating because she NEVER said that sex was forbidden OUTSIDE of marriage!

It seems that your sister already knows of her bf philandering habit. The problem here is that she doesn't want to leave him. She probably has some self esteem issues. Tell your sister to love herself more and that she doesn't need someone else to love her to know her value.

"According to him he is only staying with her because of her booby size (36c)"

This guy is a childish idiot. Time for your sister to move on and find someone who appreciates her for the person she is, not her bust size.

i think your sister is tolerating him thats why he takes it for granted

no matter what no excuse warrants infidelity

i think his just a professional cheater and uses flimsy excuses to protect himself

she should move on..........

She could try being nice to him and see if that works.

Say goodbye to him for good!

Unless she is open to such a relationship, in that case she should find herself another sexual partner too ...

Shame on you that you are her brother. You are asking this sort of Question in public Q/A. **** you.

If i were you ,, I would have killed that guy.