Not my model support the REAL OG here:

reach-around handjob while holding down with legs - Illustrious | Illustrious LoRA | Civitai

Weight:0.6 - 1.1 (recommend usually 1)
Trigger words:

hedockhj, 1boy, covered face, handjob,sitting, leaning to the side,

You can also try:

from below,arm up, face in armpit, arms behind back, m legs,

SIZE: work to vertically.