Lying Husband

I’ve been with my husband basically since I was 15. We’ve been married almost five years and have two beautiful wonderful kids, one 2.5 and one seven months. I found out he’s been talking to a random person in Mexico connected with his work possibly for months. Now my baby would have been like 3 months old when this started. He deleted everything the second he could so I wouldn’t see it. I saw only a few things her making dinner and him saying yum I’ll join you and a kiss emoji. She sent him a video picture of her blowing a kiss with hearts. He says she was just a friend and never intended anything physical but I feel that’s bullshit I never send kiss emojis and didn’t get one from him, she did. He sent a picture of his legs in pajamas in a hotel room recently to her, said he got a similar “innocent” picture.

I sent her a message on the app not to talk to him anymore and he turned in his work phone he was talking to her on.

What the fuck is this. I’m a stay at home mom. What am I supposed to do? Stay with a likely cheater and liar when I have these two beautiful babies. Who does this?