When malefic planets are present in the 4th house or in conjunction with the Moon, you will find yourself compelled to experience a sense of sensuality, even if you don't naturally feel aroused or sensual. you forcefully resort to masturbation or sexual indulgence in order ...

to artificially generate those feelings. And, You actually don't enjoy that too!
You just end up doing that without fun.
However, it's important to note that it is always advisable to engage in sexual activities when both partners are mutually interested and in the right mood.

And once i heard a sexologist once said, "Don't have sex if both partners are not in the mood or ready for it." It was something like that ...

especially malefic like Saturn and Ketu!
And 4th house = Libido