So before I go onto the story of what happened today, just want to tell the short story of my life and my girlfriend. So I have a 21 month old son, whom I have in my care from Monday to Thursday morning every week. Then he goes to his mom from Thursday night(after daycare) through Sunday. I am about 2 weeks away from me and my girls one year anniversary, and I believe she is the one. I intend to marry her. She has always treated my son great, and is always understanding that he comes first before anything else in my life. So today I went to work and asked her to watch him for an hour or so(thats all I worked today).....I go in, it starts raining, 30 minutes later, day off, so I come home about 30 minutes early....as I am walking up the stairs(apartments), I hear my son crying. No big deal, kids cry. He has two big windows that face the walk way to the doors. So, I can see him in the room crying. Didn't look like he got hurt or anything. However, I wait a second expecting to see my girl...never comes in. So I decide to wait and see how long it takes her...after about a minute straight of him crying hysterically, I decide I better go in and make sure he is fine. I open the door and instantly I see her on the couch on her computer, probably doing homework. So instantly I erupt, why the **** arent you checking my kid, how do you know hes not hurt, etc. Her defense was he just started crying and was crying for no reason...which was false. To keep a long story short, he had diaper full of poop and his sippy cup was empty. Well he has a rash, so him having crap in his diaper PROBABLY would of burned or hurt and thats why he was crying.... So I go from thinking she is the one I am going to marry, to now questioning whether I should straight up break up with her tomorrow. He is MY son, and I get that. But he is my #1 priority, so if she is watching him, he should be hers. What happened today was so unacceptable. I don't know how to move forward honestly. There is no excuse for what happened, but is that a one time deal breaker? Then again, I have to know that she is going to be that parent when I am not there. I can not be with someone that I wont be able to leave him with. Can I trust her from here on out? Im confused.....whats your thoughts?