He's always calling me when he wakes up or goes to sleep, talks to me for hours, comes to meet me after work every Sunday, opens himself up to me (whenever he wants to cry he does it in front of me but no one else) etc.
However, when I was sitting next to him yesterday, I saw that he has been messaging tonnes of girls and some of the messages would read as "hey babes" etc.
He also continues to talk to his ex continuously and she constantly sends him pictures of herself (not nudes)
I haven't said anything to him regarding this but it is really hurting to see and I also don't want him to think I'm being overprotective or possessive because he hates that.
I really don't know what to do. Should I let it go, be more cautious or take it as a red flag and leave?
Please give me some advice.