When taking her clothes off, always try to deal 6 damage (so you have enough HP to use your abilities), then spam sex until her hornymeter reaches 80% and use blowjob twice (this will increase her hornymeter to 99%) The last part is RNG, try talking to her, if you're lucky you'll get +1 to hornymeter and she'll reach 100%, when she reaches 100% nothing happens btw, she just doesn't call you useless when you go to sleep