No, it isn't okay.
You didn't want to be hurt the first time around.
You do not appear to be eager to see her with another lover.
She proved to you that she is willing to break your trust in her.
If she really needs to have this lifestyle more than she needs you, then you already lost her. If she has issued an ultimatum that she be allowed to take a lover, then she doesn't give a damn how you feel about this.
She of course has the freedom to sleep with who ever she wants, but you also have the choice to sit there and be hurt again or to let her choose to either leave you or her lover. In the end, we all choose what will make us happiest and if you really love her, you will give her the choice; if you aren't truly happy with being her cuckold and aren't ready for her to emotionally disconnect from you, then she will be unhappy in the long run because you will not react the way she wants.
You didn't want to be hurt the first time around.
You do not appear to be eager to see her with another lover.
She proved to you that she is willing to break your trust in her.
If she really needs to have this lifestyle more than she needs you, then you already lost her. If she has issued an ultimatum that she be allowed to take a lover, then she doesn't give a damn how you feel about this.
She of course has the freedom to sleep with who ever she wants, but you also have the choice to sit there and be hurt again or to let her choose to either leave you or her lover. In the end, we all choose what will make us happiest and if you really love her, you will give her the choice; if you aren't truly happy with being her cuckold and aren't ready for her to emotionally disconnect from you, then she will be unhappy in the long run because you will not react the way she wants.