?Snap chatting video calls

My husband has snap chat. He has a friend on there that he snaps a lot; so much so that she is listed as his best friend on snap. She is our age and has a child our age. He claims they only snap each other the kids. I told him it does make me uncomfortable because I don’t even know who this person is; where I have been introduced to of his friends and visa versa. We have been together 10 years- so there’s not a lot of room for secrets here.

He said he would delete Snapchat if it makes me uncomfortable- and he did.

However; prior to this conversation, we were laying in bed one night and I heard an odd ringing from his phone. He quickly shut it off and claimed he didn’t know what it was. I told him it sounded like a video chat and he stated he had no idea about it and that his phone was messed up?

This was a few weeks ago.. maybe 3 or 4.

He has deleted his snaps now, but when I was going to download some photos of our kids to print from his phone I saw this image.

I don’t know what to do or think.

Is he cheating? Even just emotionally with this woman? Am I crazy and over reacting?

How do I approach this?