For T2V, use the high and low noise models at 0.8 - 1 strength.

For I2V, use the high noise model at 1-1.5 strength with the low noise model at 0.9 strength.

With I2V, the high noise T2V model adds more motion, if the I2V version isn't doing enough.

Start with some form of "a woman uses her breasts to titfuck a man". You can tweak it, like "an irish woman with red hair titfucks a man with her breasts". You can also try adding "she is kneeling between his thighs" if you're note having any luck.

Follow that with "A squirt of thick white cum oozes out from the woman's cleavage, it coats the man's penis" for a cumshot. Increase the low noise CFG if it isn't working.

Examples are all done with T2V or I2V lightning LoRAs, at 1-2 CFG with 6-8 steps.