My SO keeps re-adding his ex on instagram and liking older pictures on her page/ ' lurking ' and we've talked before about him liking her/their pictures and that I wasn't happy with him doing it and so he says okay I won't do it, but he always goes back to doing it again! Just kinda makes me feel like he still likes her or something and I know if that was the case he wouldn't be with me but I can't help but feel some type of way about it. Advice??