SO more honest after drinking

Need to vent a little. I love my boyfriend but it’s frustrating sometimes how he is the most open and all lovey-Dovey when he’s been drinking. It’s not like when he’s sober he’s mean or anything, he’s sweet and still tells me he loves me and misses me but that’s about it. When he’s drunk though, damn is it amazing. He’ll go on and on about how much I mean to him and how much he loves me. It’s frustrating I can’t get that from him when he’s sober. How can I get him to open up?