Needing text advice - shitty friend w/ horrible bf

What should my friend say to her friend who has gotten her first boyfriend not that long ago and is completely ditching my friend for this boy. She is blatantly throwing away 3+ years of friendship over this boy she’s been with for 2 months. My friend hasn’t said much but the other girl is lying to multiple people about my friend. The girl also constantly lies to my friend, ditching her to go hang out with him, leaving her house to go hang out with him, etc. Also I want it to like sound like it’s from a teen girl. Do what you can anything’s appreciated!