Trying to help 10 yo son stop being creepy to the girl he has a crush on

I'm the stepmom of a 10 year old boy (Joe) who has a crush on the girl across the street (Karly). They are close in age and the girl has boyfriend (Ben).I have seen Joe text Karly "I can see you" while looking out our windows. We were eating dinner near windows and she was out in her yard so it's not like he went out of his way to spy on her, but I'm sure this comes off very creepy. I told him that might make her uncomfortable that he can see her but she can't see him.He has also sent texts like "💔💔💔 you and me" and "do you like Ben because it sure looks like it" to which she says "yeah". Karly's step dad told Karly that he doesn't like Joe texting kisses to her and Joe says "I don't care" (I have read text messages in Joe's phone to get this information)My husband has already talked to him about not bothering girls via texting. I know this is a very sensitive subject for Joe and he is embarrassed to have an interest in girls and just denies everything.I am now trying to find a way to get through to Joe.*Stop harassing people with your phone *You will get nowhere by being disrespectful of relationships (familial or romantic).Any advice is greatly appreciated! Thank you via /r/Parenting http://bit.ly/31bFFwH