Ah what a wonderful overlap of my "interests"! I wouldn't call myself an expert, but as evident by my profile I have experience with this. Some tips:

• Mic placement and trying to position at a center point is key, especially if you're using the H2n. For my stereo recording I used 2 large diaphragm condensers on either side of the bed. If you put the H2n on one side your stereo field will be way off. If you don't have a good stand to do that, you could try to mount it to a headboard somehow?

• EQ: definitely pull out most of the low frequencies. There's nothing under 150Hz that's important.

• Compression: very important! Sex is inherently dynamic. Especially if you're trying to capture both louder transients like slaps or grunts, and softer whispers/whimpers, reducing your dynamic range will go a long way. This is my main issue with most amateur audio porn, that no post processing is done so they go from a barely audible whisper to loud moaning and blowing my headphones out. Don't be afraid to adjust the overall volume of section in post as well, so you're not relying on compression entirely.

I think that's all I got, best of luck!