Isn't it fundamental to practice that we work to release ourselves from the sense fetters that tie us to samsara? Once released, we develop insight and cultivate this path toward Nibbana. So, the sense fetters, including lust and sexual sensuality, are part and parcel of the activities of the mind that tie us to samsara.
Now, sex with a romantic partner is amazing, right? It's really great stuff. Lab experiments with rats tell us that a starved rat will rather copulate than eat. Some of us here might understand that sensibility. Maybe the rat was a college student.
Our brains are programmed to copulate, and our brains release magnificent euphoric chemicals in support of the goal of copulation. However, with right mindfulness, we understand the "trick or treat" (10/31 Halloween metaphor, sorry) component to sensuality. It's a treat, but it tricks us into pursuit of more sense pleasures away from the path of purification.
A lot of discussion s can be held about the merits of romance and sexuality, but so long as we are still in the camp of the romantic, we cannot be in the camp of the renunciate or the stream enterer. The camp of the romantic distances us from the Buddha's teaching of the highest goal. Now, the Buddha clearly understood the nature of lay men and lay women, and understood that the lay practitioner could achieve high levels of release. Bu the stumbling block to release may be these attachments to the sense fetters that, while strong, wonderful and compelling, keep us off the fullest path.
So, as Bhikkhu Bodhi commented with respect to a different issue, it all comes down to our own individual predispositions and personalities. A kind and compassionate lay person may in fact be well on the path ahead of the angry, greedy monk. But I think the Buddha had it right that to the extent that we incorporate these renunciate practices into our lives, we better prepare the soil for the cultivation of release. After all, who wants to live like a rat in a cage? http://youtu.be/CN4oo-kn7r8