They’re bullying my daughter for their son being gay

My daughter (I’ll call her Katie) is 14 and has been friends with this boy (I’ll call him Nick) for about 4 years. Long story short, Nick is gay but his parents aren’t supportive. They’ve played Roblox together and they won’t even let him dress his character up too much like a girl and tell him they will deactivate his profile if he doesn’t change it to be “manly”

Over the weekend, Nick invited my daughter and a mutual friend to go to the movies with his family. I offered to give the girls money but Nick insisted that they didn’t bring it. Well today, Katie comes up to me and shows me her phone. I looked and his 24 year old sister added my daughter on social media to tell her that she thinks Katie is a low life and has a nasty attitude bc they play on Roblox and XBox commonly. That I must be “neglecting her” to let her do those things and not give her money for the movie. When Katie stood up for herself, it just fueled this psycho’s fire to bully my daughter. Telling her to “respect her elders”, that that’s why she’s “a shitty friend” and “will go nowhere in life”.

His father also told Katie that he is a cop, taunted her and told her that he could go through the school to “find her” and would file a harassment order if she continued to be Nick’s friend. They also told her that they planned on putting him in counseling to “fix the problem”. (Referencing his sexuality). Katie told me they are doing this to a lot of his friends.

I feel like they are having a hard time accepting Nick’s lifestyle. They wanted him to play baseball, go to college, are pushing him to get PERFECT grades, want him to get married one day, etc. But Nick doesn’t want it and they blame his friends instead of just accepting the poor boy for who he is. I think they’re just trying to hold out hope that he’ll live this “perfect lifestyle” meanwhile he’s just trying to be a kid while he still can. I think they blame Katie because she’s been supporting him in his choice to come out to friends. I understand having a lifestyle pictured for your child but I CANNOT empathize with an adult straight out bullying and taunting a child for choosing not to live out that lifestyle! How would you handle this??