Version 2 is more potent, so weights in conventional range of 0.3-0.8 may be best. It'll also do more unprompted, e.g. making the gal smiling, flushed, and sweaty.
For prompts I'd start with "Mpov_fdom, 1boy and 1girl, sex, from below."
Femdom_Straddle-000011.safetensors