Sex and Christianity

So my bf wants to continue to have sex in our relationship but I don’t. What do I do? Here’s some back story to help. In the beginning of our relationship we were having sex a lot/me sending naughty pics. he wasn’t in faith and I was falling in faith but now a year and 7 months later he got baptized because I helped him find God and now I’m soon going to be baptized again because I found God in a new light. He wants to still have sex and me send naughty pics despite us both now being devoted Christians. He also wants to be a pastor now. What do I do? I know what’s right and it’s to not have sex but it’s not easy to get him on board but he’s on board with no pics. I already asked our pastor but it didn’t help. What do I do! (Also I’m 16 and he’s 19 it’s legal where we live)