Hate the way he kisses

I don’t like the way my boyfriend kisses. We were long distance for about 8 months and we’ve been back in the same city for one months now. I don’t remember this... but I don’t like the way he kisses now that I’m back. He uses the inside of his lips to kiss me so all of our kisses are super slobbery. I don’t know how to mention this to him without breaking his heart. What should I do?

It gets so bad that I just have to stop kissing him and I push him away which is eventually going to make him sad.