You should use your favorite uncensored checkpoint or LoRa with it, not alone on Krea2.
I use Kroma (Silveroxydes extracted LoRA) at 0.8-1.0 but other ones tested worked like Realistic Engine Lora, or homo fidelis checkpoint. It works similar to Krea2- 69 LoRA but more accurate for males.

For prompts you can use "mutual oral sex in 69 position" to help.

Not 100% accurate, the position is tricky and you might need to test several seed as the lora is fighting krea trying to put them usually face to face (if you use preview you will instantly see if it fails).