Actually a wholesome, yet realistic approach, to writing a sex scene for 2 teenagers who know nothing about sex and is experiencing it for the first time. Both MC and FMC even intentionally DO NOT look up any tips/advice to make the sex "feel better" because they want to experience the ups and downs for their first time together, and learn from it by themselves. So many romance stories have characters finally having sex for the first time, and immediately having it being the most amazing thing to ever happen to them, when in reality, it's an awkward situation where you don't really know what to do to make each other feel good, other than trying something and learning from it.
I've linked the WN in English below if anybody wants to read it. Unfortunately, it'll probably take the manga 10+ chapters to get there, so at least a year (1 chapter/month). To put it into perspective, we just finished Chapter 40 in the WN. The English translation isn't the best, but it's readable.
Chapter 74 from WN:
https://dasuitl.com/wn/after-i-save...d-the-maximum-capacity-of-love-and-happiness/