I get mad when my friends comment on my girlfriend's photos and say she is cute snd pretty, is this okay?

should I be mad when they just go on one of her photos like two minutes.after i comment on it to tell her a cokpliment and they say stuff like cute, looks good, pretty and she says thanks. Should I be mad and tell them to stop or should I take it as a compliment becsuse Im dating her? I get really angry and jealous easily at times..