Cums really quickly need thoughts

So I took my boyfriends virginity. He is 17. We've had sex like 5 times altogether. Last time we had sex, he came in like 5 minutes. We did no condom for the first time. We made out then he fingered me, then instead of having sex again, he asked for a Bj! Usually in previous times, when we used a condom, he would cum multiple times without stopping(taking a break)! What do you guys think changed? Also we only have ever used missionary. Give me your thoughts please! Thanks guys. Xoxo, Destiny