it was my girlfriends birthday yesterday. to celebrate we went to nagnagnag (i've just got back), we were having a fun time. i went to the toilets but they were being cleaned so i got sent back and caught my gf kissing a guy we both know and who i trusted. i comfronted her and she seemed to reluctently accept it to be the truth. i got a cab home with my gf as i was scared she'd get hurt on her own. im now in my room on my own thinking...what should i do?