when i when i text one person with a iphone the message show up green but everyone else i text with iphone the messages are blue

So when I text my boyfriend phone the message turn green and not blue but when i text others with iPhones there messages are blue plus when I go to his contacts the FaceTime button doesn’t show up I have to put in his iCloud just to FaceTime now on my end my iMessage light is on in the settings he claim that his is turned on anybody what’s going on