I genuinely did not think you’re trying to insta-butt us. Just letting you know that even if you were poking it out a bit one could tell from the first picture that you just have a big ass. If you want some advice, do seated hamstring curls, and sit forward to get an additional stretch. Lying ham curls can still target the glutes a bit. Seated ones will get you a better stretch and in theory not let you get a full glute contraction, even if it’s inadvertent.
Lower back is a bit harder to hit without getting some glute stuff in, but something like zercher Seated good mornings might help.
Besides that, my main point was, trust me, if girls are commenting on it it’s because they like it. If you think them saying one thing about it means that that’s what they think, you may be mistaken. I have a big butt, probably the same as yours if my back and hams were smaller. It’s better than having a pancake ass. Find a girl who fiends for it.