How can I learn to be a better bottom?

It's debatable how long I've been dating my boyfriend, but, we've been having sex about 10 months now. He's not the type to really open up emotionally to give me a feel for if he needs something or if something bothers him. I sometimes wonder if he really feels much at all. This is not a criticism because he makes me very happy. This is also not as big of an issue as it may sound as we're really happy together and our relationship seems to be progressing really well.I recently a couple weeks ago realized I may not be up to pat sexually with what his standard might be. I think he's dating some way better looking and way kinkier guys in the past and really sure what that fully entails. He had this one ex who got as crazy as fisting but he didn't want any part of that he said and that went down after they broke up. But it's clear he's explored everything.Another problem is that he's really really huge. I've noticed he holds back a lot in fear of maybe hurting me.Are there some easy ways to approach this? Is there a way to maybe push my body to "take all of it" or ways to maybe initiate something more exciting?Last issue. He seems to be a guy who doesn't care for monogamy and I'm the opposite. Has anyone dealt with this.