He doesn't like to kiss 😚

Please help and explain to me why my boyfriend doesn't like to kiss me. We been together for a long 3years I say that because we been off and on. We have sex all the time like all the time and we do everything or almost everything (no eating ass) but anyways we when have sex he doesn't kiss me, when I try he move his face slowly. First I thought it was my breath nope that not it I don't what it is.