<human>: Provide a brief overview of the text.

The title may actually sound worse than it is.

**Short back story:**
We're all studying in the same semester, close to graduation. My best friend (unfortunately 'the guy') screwed with a girl in one of the first semesters that later became my GF. 

I did not know about all that until we came together. They didn't have a relationship and everything happened before me and my GF came together. So she didn't cheat on anyone.  When I found out I was extremely mad, she apologized and cried a thousand times (although it really wasn't anyone's fault). She didn't even really know me when she was screwing my buddy back then.

**So here we are now almost a year later.**
 I love my girlfriend, our relationship is perfect and I trust her 100%. My buddy and I (being guys) never talked about it and acted as if it never happened. 

Besides our studies my buddy and I started a small startup and so far everything is going as planned.  In summer my buddy and I are doing an Internship in London so he asked me whether I wanted to move in to a shared flat with him. It is super hard to get a affordable flat alone and besides that we could work on the startup in the evenings. 

*Everything seems perfect right? Well - No.*

My girlfriend wants to visit me for two months and the situation between them is still unclear. My girlfriend said she is fine with us moving together although It probably will get weird. However she is willing to pour oil on troubled waters. 
 
**What should I do?** It would probably make sense to talk to my buddy although I have no Idea how since we almost never have super serious or deep conversations. We're both kind of emotional cripples.
Or is it a bad idea in the first place and I shoudn't even consider moving in with him? (Although practically it would make a lot of sense.)
<bot>: Want to move in with my best friend (for three months) that screwed with my GF before we came together. Bad Idea?