Am I overeating?

Amber
My wife has this friend that I can't stand because she's a known whore and homewrecker. My wife and I worked together until about a month ago and when this friend started working with us, I told her to stay away from her because of how she is (I went to High School with the whore) well my wife is the type of person to be friends with everyone so she started talking to her. I've begged her to stop, because I know what's going to happen, we've had plenty of fights because she keeps talking to this girl. So my wife has been telling me that they don't really talk that much anymore, just at work occasionally. Well I found out last night that my wife has been texting her behind my back and just deleting their messages. I know my wife hasn't cheated on me with her because I obviously know her work schedule and she's home right after work and she talks to me on all of her breaks, so I knkw she hasn't cheated with her, but I'm devastated that she's been texting her and hiding it from me. She said she hid it because I got mad when they would talk, but my thoughts are, then why couldn't she just not talk to her? She's nothing but a slut and she's not worth losing a marriage over, plus we have a baby on the way. She says I'm over thinking things but talking to someone and hiding it seems like a huge deal to me, especially when I've begged her not to talk to her.