He wants to put up a photo of a memory that is clearly special to him-with another woman. No doubt part of the warmth of that memory is his having been with her. How could he be so heedless of your feelings? Maybe if you two had been married for 50 years and had a lifetime of memories together, you could laugh off the photo and tease him about it. That is not the case. At your stage of the relationship, he should still be so smitten with you that his finding a photo including another woman should have made him uncomfortable. If he can’t Photoshop her out of the photo, he should not have even thought of hanging it. The fact that your feelings about the photo weren’t paramount is a danger signal. If you want Mr. Right, then leave. If Mr. Right Now is O.K., then, if you stay, just know that is all you have.