Why did his homeboy sent him a picture of a girl

So I get into my boyfriends messages and his homeboy sent him a picture of a chick and I told him “why is your homeboy sending you a picture of a girl ?” And he literally tells me he doesn’t know .. so his homeboy just sends him a picture for no reason, I said , “I’m not stupid , I know ya be having that guy talk , I know you just didnt stay quiet about that picture “ then he tells me “her body looks fake , I’m not into girls that look like that “ and his cheated on me before, I caught him flirting with other girls on Instagram before and he literally deleted his Instagram account, pulled that Travis Scott move on me , I always check to see if he still has that Instagram account and he doesn’t . I hate that I have to check and see if his being loyal or not , he even did it when my father passed away . My father died in October and I caught him flirting with a girl in November. It makes me feel ugly and I’m tired of this . He doesn’t deserve me and I’m so good to him . this is really hard to open up to , I go threw so much , I cry about my dad and go threw depression . I know this is a lot . but yea I go threw a lot of depression, and especially about my fathers death . Sometimes I hide when I cry just so my boyfriend won’t see me . Idk all of this adds up and makes me think like “wow my boyfriend really is a piece of shit “ please no negative comments