in that case your question is misleading.
He found someone attractive, we will always find another person attractive whether we are in a relationship or not, that's normal. That doesn't mean he wants to go further with the girl.
You should relax. And don't read private text messages.
But yes Venus in gemeni is fickle... at least for this question, he is looking at other women. But so do many men. Check his natal chart, it might give some more clues.
I can't stand the person I love finding someone more beautiful than me
Its his natal
Please I need yout thoughts