Snowderboat 

The act of ejaculating onto a woman's breasts, then proceeding to motorboat said woman's breasts into your own ejaculate.

I blew a load on her tits, then snowderboated her.

Snowderboat by Envizzle October 18, 2016

showerboat 

A combination of a female receiving a golden shower from one person (male) while a second person (male) is motorboating her.

Also known as a Montreal shower boat

Unfortunately, Grace was not up for some showerboating last night.

showerboat by J VanderSnoogen September 2, 2011