Me and my girlfriend have been dating for 2 years but her family moved out of state so we’ve been dating long distance for 6 months now. I visited her and stayed with her for 2 weeks about 2 months ago. We started school back up again but she has no friends at her new school. She’s taking driving lessons in her state and she got put with a random guy our age as her partner. They became friends and she talks to him quite a lot but she doesn’t talk to him over me (like if i want to facetime or something). She went to his house during lunch, its across the street from the school, and his parents and siblings were all home. When i found out i felt really uncomfortable that she did that without even saying a word to me, the only reason i found out was because she posted his dog on her story on snapchat. I don’t know if she would have told me otherwise (I’m pretty sure she would have though). I told her that im not comfortable with her going to his house and she said ok. But today during lunch she had no service and  i kinda freaked out texting her what she’s doing and why does she have her phone off during lunch (because why would she not go on her phone during lunch?) and she had service again at the end of lunch. She said they were just walking around the school and she must have gone into a dead zone. I want to believe her, but everything points to her going to his house again and keeping it from me, so I don’t know if i should trust her completely. She seems completely normal when we text/call, like he doesn’t even exist but she does talk about something he told her. I’m 80% sure theyre just friends and nothing more but 20% of me feels like somethings up.