His brother helping me out??

Queen

So glow the guy I'm dating we been dating for almost 6 months and it been alot of downs but some ups too. So we started dating really in July of last year and I met his brother in August of last year. His brother is younger but he is mature. So it be times that my boyfriend will have long talks with his brother about things on the phone that he say he call me back....that's cool I didn't have no problem with that then when I will talk to his brother he will tell me that my boyfriend is saying lil things behind my back about me so I will ask him is that what he really is doing and he will say yes to different things(that was like couple of months ago) then last month he screenshot me something on his phone and it had dating websites at the top I asked him about it and he said he downloaded them when he broke up couple of months ago but we only broke up for like 3 days at the most...so that prove he is quick to move on but this morning his brother tell me that my boyfriend don't claim me and always saying different stuff to him and they other brother