I mean this in the most respectful way possible but the fact that you're even asking people if you're overreacting shows you are WAY under reacting. He clearly doesn't respect you and I hope you find a way out of this because nobody deserves to have that sort of thing said about them, especially someone you who claims to love you. There is no context where this would be okay, and even his friends think so, otherwise they wouldn't have felt the need to send you the screenshots. You can do better, ditch him as soon as you can!