NO HATE just a question

Been with my boyfriend for 6 years now*****If a guy says that a girl is beautiful...will he always think she’s beautiful? My boyfriend once told me that this girl at his school was beautiful and she was a cheerleader so we would go to the football games and everytime she would be cheering he would stare at her and I can see it in his eyes. I confronted him about it and he said he doesn’t want to get with her. But I’m real question is once a guy says a girl is beautiful will he always think she’s beautiful...?

EDIT: everytime we would go to the games he would cover half of his face so I wont be able to see his eyes. And today he had his sweater on his face and she was there cheering and he would slowly look down like if I didn’t notice and I don’t mean to get mad at him but when we go to the games I’m not looking around at guys I just watch the game. My boyfriend never looks at the cheerleaders when that girl isn’t there oh but when she’s there he’s over here looking down at her.