In the context of marital act:
the massages in human fashion, the caresses in human fashion, the kisses in human fashion, the suctions in human fashion, the touchings in human fashion, the licks in human fashion, all stimulations **(in the human fashion) **on all the body of the other, even on sexual exterior parts of the other, are morally permissible, by nature and by essence;
all her body, her erogenous parts and even her external sexual organs, can be kissed, caressed, touched, massaged, licked, sucked with love and** with tenderness by her husband; **
all his body, his erogenous parts and even his external sexual organs, can be kissed, caressed, touched, massaged, licked, sucked **with love and with tenderness by his wife.
**
Per se, those conjugal sexual touchings are not immoral and thus they are not sinful. The fact of saying the contrary is not very normal, is not natural and thus is not very catholic, in my humble opinion. Those acts are natural. The moral view of Ronald Conte jr seems to be very wrong and unfair.
**
Definition of each sin is the key??? When catholic church is talking about the moderation, that means that the act is morally permissible, per se, only the lack of moderation can be immoral. The debate is on the constitutive element of the moderation, the debate is not on the nature of act. **