What are your thoughts?

My friend is pretty weirded out atm. Her boyfriend has his ex's mum and dad on Facebook, he lived with his ex and her parents at one point so he's fairly close with them apparently. Anywho, my mate noticed her bf likes the selfies of his ex's mum. Like loads of them. She's shown me pics of this woman and she's super young/good looking, the selfies aren't just run of the mill either she's showing a good amount of boobage and hell if I didn't know better I'd say she was in her 20s (his ex is 22 so she's bound to be in her 30s at least). Would this concern you? If your bf was liking photos of his ex's mum. Him and his ex split May 2018 because she cheated on him repeatedly and treated him like shit. What are your thoughts?