Serious sex question

How do I get my boyfriend to last longer? We’ve been together 8 months. Have sex like 4 to 6 times a week. He still doesn’t last any longer than when we were in our “honeymoon” stage. He always gets me off orally so that’s great but then penetration lasts like 3 to 5 mins max. I cut him off of oral last night so he wouldn’t get too excited before penetration and I bought us like an extra minute, maybe two. I’m mostly satisfied with our sex life but I want longer periods of penetration so we can get more experimental, even try anal, which we have discussed verbally. There’s been a couple times where I can get him off orally and he will stay hard for round two. I thought it was fool proof, but last time he got off and went soft and needed a break. So it’s not fool proof. I’ve looked up expert opinions and magazine articles but I need real people opinions. Tips to make him last. And go!