We do not yet know the dialogues, but it seems that it is Bulma who is flirting with Son Gohan.
In this dôjinshi, this timeline, I wonder if Bulma has already made love with Kakarotto in the past or she will jump at the chance and fuck his son because she sees his father in him.
For me, Bulma has always been attracted to Son Goku and Son Gohan (in the manga we can see that) and therefore, this idea of Bulma wanting to fuck with Son Gohan is excellent, Yamamoto-san! 👍
Bulma is attracted to male Saiyans.