My (30F) boyfriend (30M) wants to "break up" temporarily so that we can "date" his ex.

My boyfriend and I have been together for 11 months and everything is going great. He has a trip planned with his friends in December and he told me that one of his exes will also be going on the trip with them. Long story short, he said that she's going to be upset if they're still together but if we "break up" she'll have fun. He said it's not a big deal because we'll get back together once the trip is over.<br><br><br>EDIT: Once you guys stop messaging me saying "he's cheating on you" and "you're stupid for even posting this" maybe you can give me some advice on what to do. I just want to know how to approach the talk with him.<br><br><br>Another edit: First, thank you all for the comments and the messages. Second, I've known this guy for 5 years. We met at uni and we became friends. We would hang out sometimes and we got really close. That's why I trust him 100%. I sat down and talked to him earlier and he told me that it's not what he meant. He said that he only wanted to have a little "party" with his ex and his friends, to get some ego boost, to feel wanted again. He said that he didn't want to have sex with her and that even if he did, it would mean nothing and that I should trust him. He looked genuinely not happy about the whole thing and he even cried a little bit (not sure if it's genuine or not but I really hope). He said that he was genuinely upset about the whole situation and that he feels like he's being cornered and blackmailed because his friends and his ex are pushing him to do this. He said that he didn't know what else to do. I told him that I'm not okay with it and I suggested that we break up and that it should be for good, not temporary. He started begging me to stay with him and he said that he'll do anything to make me stay. At this point I'm so confused. Idk what to do or what to think. I feel like I'm just a dumb chick that got cheated on. He told me to take all the time I need and think it over and get back to him. I will probably call my girlfriends tomorrow and ask them for advice but right now I'm just so confused.<br><br><br>EDIT: so apparently he never had any plans of breaking up with me. He said that his ex threatened to tell me about them hooking up if he didn't but he said that he never had any intentions of actually doing it. I'm sorry if I caused any confusion with my previous edit. So he said that the two of them (him and his ex) have been hooking up for a while now and their friends also knew. Apparently his ex was okay with him dating me as long as he was still hooking up with her but she told him that she won't be okay with it if they're still together during the trip. That's why he came up with the whole "let's break up" thing. He never meant it and he never had any intentions of actually breaking up but he was afraid that if he didn't she'd tell me about them hooking up (which she did anyway lol). He said that he didn't expect me to take the break up so seriously and that he didn't know what else to do when I told him that I was okay with breaking up for good. He said that he never expected things to go this far. He begged me for a second chance and he promised me that from now on everything will be honest and transparent, that he'll do anything to gain my trust back and that he'll never do anything like this ever again. I'm in confusion and I still don't know what I should do. He cried for 2 hours and begged me to stay with him and I'm just really confused. I will probably ask my girlfriends for advice but at this point I still don't know what to do.<br><br><br>ANOTHER EDIT: omg y'all I just woke up and I still have messages pouring in. Thank you so much for all the advice. I probably won't reply to any of the comments but I just wanted to let you know what happened. So he called me at around 7pm and asked me if I've made up my mind. I said no and he asked if he could come to my place to talk to me. I said okay and he came at around 11pm. He was crying again and begging me to stay with him. He said that he doesn't want to lose me and that he needs me in his life. He said that my presence makes him a better person and that he really wants me in his life but he still wants to have this "party" thingy with his ex. I don't know what happened but somehow he managed to convince me to stay with him. Idk why and for some reason I really want to believe that he's telling me the truth. He was honestly crying so much and he told me that without me he's a complete loser and he really needs my help. I was trying to wait for my girlfriends' advice but he was just begging me so much and I couldn't take it so I said yes. He said that he'll do anything to get my trust back and that he'll be completely transparent from now on. I said okay and I told him that if I catch him lying again, I'll instantly break up with him without any questions and he said okay. He looked genuinely happy and said that he's really happy that we're okay now. Right now I'm just scared that my girlfriends will get mad at me but overall i feel okay. Thank you all for your advice.