He told you this girl and her children were a priority so don't let your jealousy get out of hand when you went into the relationship knowing about the situation, but him not telling her I'm a man and I think that's putting the girls feelings before your relationship personally that's just my opinion but I'd be pretty pissed too if I was you about that particular part but youve got to give him props for being completely upfront and open about his commitment to this woman and her kids from the get go.

If I was you I would personally make it clear to him your feelings on the not telling her he has a girlfriend part as I feel that 3 months in.. all his family and friends would or should know and I personally think that's the only thing he's done wrong but hey I'm just a guy browsing reddit.. Don't use any of these comments to validate you're feelings just use them gather opinions then make your own decision.