would you be concerned?

so my partner and i have been together for 8 months… in the past i’ve found he’s been talking to girls over snapchat (as friends) but he deleted the conversations, i had spoken to him about it in which he removed them off his snapchat… we broke up back in december for a few weeks then got back together now in this time he’s readded 2 of the girls…

my biggest issue now is, he won’t open snapchat infront of me, last night he was talking about a photo i saved in the chat of him and he wanted to look at it, i had stated my phone was on charge and i wasn’t getting up to get it when he had his phone right next to him so i had said it’s saved in your chat aswell but he refused to go on it infront of me.. i do trust him but i’m not sure, this just doesn’t seem normal to me 😕