Tips for safely exploring sexual intimacy?

My partner and I have been in a relationship for a little over three years and it has taken me a lot of time to truly feel comfortable with sexual intimacy. We've been doing those things, on and off, from the start. But for me it often feels like a "side quest" or a "performance", like a thing that's separate from cuddling. Like love and lust cannot co-exist for me. I know for a fact that I am not asexual and I need this, but it's just hard. I can't make it happen naturally and stay in the moment. I brought this up to him and he said that he also noticed our sexual activities are all very routinely. He wants to experiment with just spending a whole night being naked and taking our time doing stuff, chatting occasionally, maybe getting up for a drink, but just to try and not make it an abrupt and brief cutscene in between doing lovey-dovey things. I agreed, although I just genuinely cannot fathom it. Do you not need to be in the mood? Can you stay in the mood for hours? Can you just do these things on and off for a whole night? I guess we'll find out.

What does sex/sexual intimacy look like for you guys? And does anyone here have any tips for allowing curious exploration without inadvertently triggering yourself? Maybe this situation is a little too unique, I don't know. But I decided to ask here, in case anyone has in fact been there done that.