No, that's not so. As Bastet said, she is not showing any interest in looking up the bartender and continuing whatever the kiss started; she has no relationship with her. When she spoke to her husband, she said clearly that she did not want to 'open' their marriage (bring a third party in - that is, another relationship). She wanted him to know about this tumult in her feelings she was having, and that she has the intention of 'exploring' that through the non-adulterous medium of her acting.
The unspoken corollary means that exploring those feelings MAY in fact lead to a relationship in the future, if she eventually decides they are strong enough - which she will presumably be as scrupulously honest in warning him about IF it happens. Because she's made up her mind to mentally explore the possibility, she's doing the honorable thing by giving him warning of it and giving him the choice of deciding if that uncertainty is something he can live with or something he can't. And for him to make a fully informed choice, he needs the unvarnished truth about how things stand - including the strength of her feelings about what happened.
Why should we pick sides to root for? I think she acted honorably in telling him the truth, and I don't think he did anything wrong in choosing to respond, "no, I can't live with that uncertainty, don't expect me to wait around for you while you do this." That's his choice to make, and it seems to me just as honorable.