Down today

Had an argument with my SO that left us in separate rooms. It's better this way for now that we just leave each other alone for some space. Basically I confronted my SO about what he's been doing, talking days and weeks about a particular girl. So finally today I confronted him asking why he's always talking about this girl. And he got upset saying I've got issues. Seriously ladies, tell me, am I in the wrong for asking my SO who and what this girl's relationship with him is if that's all I hear him talk about. So she's just an acquaintance he met through friends. Okay..???...so is he that interested in her to the point that he updates me on what's she's posting on her social media.?? He said he would be fine with me if I was saying some guys name to him for weeks...he wouldn't think anything of it. Wow. Just wow. I'm shocked. I know he's faithful but he got real defensive and even raised his voice at me when I asked him about this girl.

I don't feel I'm in the wrong. As his spouse and with our baby on the way I have every right to ask him questions because I don't like what he's doing. So what it comes down to is I'm the one who's got issues and there's nothing more. *deep sighs*

Why are some men so stubborn to admit some of the things they've said or done. Why can't they be honest if they want our Trust?