Snapchat😒

So this morning my boyfriend had 2 snapchats from his ex and didn't open them until I asked him what she wanted. I didn't see what they were but I saw that he had a 9 day snapchat streak going with her. My ex boyfriend was cheating on me by snapchatting one of his ex girlfriends racy stuff. Am I justified in thinking that it's weird and that it makes me uncomfortable or am I being too dramatic?