Boyfriend going to dinner with ex girlfriend ??

The guy I’ve been talking to for about 3 months now just told me he’s going to have dinner with his ex girlfriend of 3 years... am I a bad person to not be okay with this?? When we started talking originally she started adding me on everything from Facebook to snapchat and has been texting him almost everyday... it doesn’t sit right with me and then when he told me they are going to dinner tonight as “strictly friends” it still doesn’t feel right. Do I say something? If I did, what would I say? I’m upset about it and it hurts me a lot but I don’t want to sound controlling or toxic... please help!