HELP!!? IS THIS SEXUAL HARASSMENT???

So I just got home for winter break and my mom told me about something my sister told her. We have very close family friends, I’ve known them my whole life, and the mother is my godmother and her daughter is my best friend. Her little brother is like a little bro to me too.

But the thing is (he is now a high school junior) he’s gotten very sexist and racist and overall very bigoted and almost intolerable to be around these last few years. I did what I could to kind of educate him but he was not having it, his father is the same way very misogynistic and verbally abusive and degrading to my godmother. I wasn’t surprised he would begin to see things his fathers way and follow in his footsteps. Now whenever I go over to hang out with my bestie I cant make it thru a convo without him peddling his bigoted horseshit and it ends in an argument.

Anyway back to the point, my sister told my mom he’s been snap chatting her that he thinks she’s cute and he likes her (bs he does NOT he’s just buttering her up cause he’s always been dismissive of her) and he’s been constantly asking her for pics of her in tights or nudes!! I was not surprised just really disappointed tbh and my sister was traumatized and crying (she’s a freshman in high school and she didn’t know how to react to this) and neither do I!! He ruined whatever relationship we’ve had all these years with this and I would love nothing more than to set his shit straight, but my mom wants to talk to my godmother about it (I think we will have to eventually anyway we just aren’t comfortable going over anymore after this) should I talk to my best friend about it? Should I threaten him about going to his mom or just do it? Should I not talk to him at all? Idk what my sis want to do yet she’s still shaken and he sent snapchats after that she hasn’t opened any in case they’re worse (btw she told him right after that he’s a creep and to knock it the fuck off but he didn’t, he doesn’t take no for an answer and constantly jokes about rape in the past)

But his mother is also very conservative, I have a feeling she will only say ‘boys will be boys’ and tell my sis to ignore him or not dress older than she is (bs).

IDK WHAT TO DO OR IF I SHOULD DO ANYTHING??!! Is this even harassment?? I think it is but I’m not sure! Pls help?? 😭