Yes, niramisa sukha is the better “pleasure”. But you can only realize this when you walk a good distance on the path or are at least Sotapanna Anugami. Also, the realization that immersion in rupa is suffering comes only then.
Sexual conceptions are obviously a widespread problem. This can also only be seriously addressed from Sotapanna level. Then one contemplates more deeply about the functioning of paticca samuppada or the mind, citta, cetasika, … And only then the mind can slowly grasp the uselessness of sex (form/rupa, contact/phassa …), although the perception will still be distorted for a while (sanna vipallasa). All this has to be thought through to understand the nature.