Yes, she can't look like a slut when she is with me

It's very hard to confront her. I know she is technically my second girlfriend but the first one wasn't real I think. I mean I coudn't even kiss her and she cheated on my with my best friend. Who is still my best friend?! After he literally borrowed a condom from me to fuck my ex? Not to mention my ex left me for him?! What the fuck was wrong with me?? And the most funny part is that my actual girlfriend Kitty chose him too first! Haven't I mention this earlier? Maybe I should tell you how she became my girlfriend because we were together for a long long time....

Some weeks earlier, when Natalie was my girlfriend we went to a party together. Me, Natalie, Mark, and Kitty. My relationship was very fresh with Natalie at this time. Maybe 1-2 days old. We weren't too sober and we were having a really good time. We were dancing when Kitty came over to me. She wanted to talk so we went out to hear each other better. She told me she has a crush on Mark but he doesn't seem to be intrested in her. She told me Mark asked her if he could fuck her tonight but Kitty refused it. Every one of us was virgin back than. Kitty didn't want to loose her virginity like this so Mark was a total jerk...I don't understand why but Kitty still wanted him so she asked me to help. I told her I'll do what I can and we headed back inside. We went back to the exact place we left our friends but they were missing. We searched for them for about half an hour but we couldn't find them so we started to dance. They came back an hour later and told us that they were searching for us. We laughed than went home. Maybe this was the time Natalie first cheated on me???? I totally trusted her, our relationship was only 1-2 days old and she already cheated...What a fucking slut...and that's not everything. When Mark and Kitty was not there, when we were alone she Natalie slapped me and confronted me about going away with Kitty. I told her what happened but she couldn't belive me. She slapped me again and told me not to lie...We were arguing for hours than she told me if I can go alone with her girlfriends than she can be with my friends too. I didn't take this seriously enough because I was faithful and I trusted my friends. Oh what a naive I was....