Sucking is ok but licking is not ?

Hi first of all i hope you excuse my English, my boyfriend just told me that its ok to suck dicks but not licking a vagina ( we still didn’t do neither we are planning for future) and he says that sucking dick is just something external and not the same as pussy cause it’s internal and have discharges and i guess he implies that licking is gross and sucking is not and not gonna lie i am kinda upset about what he just said cause its not like i am sucking for you because i am dying to do that i think its a bit gross too but i will do it for you so can someone tell me if its really different? And if its real that sucking a dick is ok but not a pussy ? And please give me responds that i can say to him next time we bring that up