Idk how to feel?

So my fiancé and I went into the gas station, and as he was paying for gas I had to use the bathroom.. and I as soon as I get out the bathroom, I hear here him say “ you too baby” to the cashier ( the woman is just a little older) and I confronted him about it and he said he didn’t mean it like that.. but idk. I’m very weird about shit like that while in a relationship.. pet names like that shouldn’t be said to anyone but your SO! Am I wrong for how I feel? How would u react to it?