For me what makes man sex so enjoyable, is the distinct changing phases of the experience. From the uncertainty of moving into position and the spreading of legs to that point of giving myself to the guy as he gets between those legs. The entry painful or not, then the fucking, building to the acceptance of enjoyment by both and certainty of a powerful orgasm. From a little awkwardness and anticipation before to the willing acceptance of rush the orgasm after.
Really get into the tell tale signs that the guy is about to cum. The rougher sensation of the fucking between us, and him being more distant and strained with face contorted then finally letting go. The release, a flood of short jabbing thrusts full depth and grown wet warmth in me.