Found inappropriate texts on boyfriends phone

Last night I found lots of photos of a woman on holiday on my boyfriends phone. This woman is a customer of his and he had requested the photos. To top it all of he texted her back “you look very hot” I have an issue with this. It is obviously inappropriate as she is his customer. He however is saying that I’m completely over reacting as it was just a complement. Please could you give your take on this

Oh no , no , no....there is no way this not "unappropriate"...And if you put up with this (meaning you stay in this relationship) than he will see more of this or he will just learn how to hide it better :( Its never appropriate to receive those types of texts when your in a relationship.

That sucks! But I know exactly how you must be feeling right now! All I can say is do what makes you happy day by day, there is no real right thing you should do but just know he is a shady guy that isn’t respecting you by doing these things and you should probably start pulling yourself away