Boyfriends female friends

So my boyfriend and I have been together almost a year. We have a history of him being a little to friendly with other women especially his exes. I caught him flirting a few times and he has been sneaky and lied about stuff before but we've moved past it and he's been trying to be better and I'm building trust again. Still hurt from the lies but trying to move on. Yesterday I found out that he texts everyday with a friend of his that he went on a few dates with years ago. He said they talk a couple times a day. I find it odd that after everything we went through with other exes he never mentioned her before. A lot of his female friends are exes which I find weird especially since they were all short relationships. We've talked about how he keeps in touch with exes but never mentioned her because he "doesn't think of her as an ex" since it was so long ago and just a few dates. My question is do you think I have a reason to be upset? Would you feel weird if you found out your man was texting another woman every single day a couple times a day? Especially given the history of flirting and lying.