Gf leaves for 3 hours

Me and my gf have been dating for almost 4 years and we have been playing around with the whole cuckold concept but have never done anything other then it being a fantasy. Lately she has been texting a couple of guys that she used to be a thing with and all of them have asked her to go out for coffee or things like that. Last night she decided to actually go through and grab coffee with one of the guys. She texted me when she left and then left for 3 hours until after midnight. She texted me once throughout the 3 hours saying I’m having fun. When she got back I asked her about it and all she said was they talked and listened to music. Did something happened that she’s not telling me?