i got in an argument last night

last night when my girlfriend and i got home from work. she decided to pick up my phone which i dont care about that i do it to her and she never complains. i go through hers and she goes through mine its ok. it dont bother either one of us. but she looked at my text and seen that i was texting trevor and me n him were talkin about hanging out. he asked me what i was doing this weekend and i said i didnt know that i would probably be with her and try and hang with friends.. but the thing that made her mad was the fact that he asked to hang with me like she read the text that said i wanted to hang with her but in her mind she thinks that i dont. is that right? i dont think it is, we got in a little pesky argument for no reason last night because she thinks and feels that she is keeping me from my friends when i have told her that i love to spend my time with her because i love her. i dont need to hang with my friends when i have a wonderful girlfriend that i can hang with everyday. i just dont think its right for her to assume i wanna hang with my friends when all i really want to do is be with her.