Boyfriends ex is trying to say it's his kid

I've been dealing with this for a while. Back when my boyfriend was 17 he moved back to his dads which is a very run down area where everyone sells their child for meth. My boyfriend was on pain meds after a surgery and some girl got on top of him and started having sex. Turned out she was 13. She continued to do it whenever he was out of it and he said they always used a condom. Her and her sister got him drunk one night after he told her he didn't want to sleep with her anymore, she forced him to come in her. Couple months ago she tried sending me a Facebook request and sent me video of the kid who is probably almost 2 saying I took away the kids dad. At one point he did believe that was his kid and gave her a suggestion for a name which she used. He hasn't contacted her since but she's been making fake profiles of him saying he now has 3 kids and 3 different girlfriends when I've been with him this entire year. I know it's fake based on how we live together and work together and these people are claimed to live on the other side of the states. His brother doesn't believe it's his, but his dad is trying to play it off on Facebook to look good for his tribe. Thoughts?