This is a fellatio in which the male organ is stimulated by the mouth shortly after ejaculation as an afterthought of the sexual intercourse.

Prompts:.
osofel,1girl,hetero,cum,cum in pussy,penis,1boy,oral,after sex,fellatio

*Models weak in male model description may need to be strengthened to get it.
Female positions vary per "squatting", "spread legs", and "lying".

Option prompts:.
another's head→Male patting female head
tongue out→man sticks out his tongue and licks his dick
cumdrip -> semen may become stringy

This is an after-the-fact depiction, but it could be used to create an illustration of a cock coming out of the side and sucking on the side of a woman's head.

I think it can be done in various ways, so please give it a try.

本番系エッチの事後として、射精して間もない男性器を口で刺激されるfellatioです。

プロンプト:
osofel,1girl, hetero, cum, cum in pussy, penis,1boy,oral, after sex, fellatio
※男性モデル描写に弱いモデルは強めないと出ないかもしれません
女性の体位は「squatting」「spread legs」「lying」あたりで変わります。

オプションプロンプト:
another's head→男性が女性の頭をなでる
tongue out→ちんこを舌を出して舐める
cumdrip→精液が糸を引くようになるかも

事後描写想定ですが、横からちんこが出てきて横向いてフェラするイラスト生成にも使えなくもないです。
色々出来ると思うので試してみてください。