If your prospective partner is not specifically repellent, and there are enough of the appropriate hormones built up in your system, physical response is no pro

If your prospective partner is not specifically repellent, and there are enough of the appropriate hormones built up in your system, physical response is no problem, if emotions are just right, if there's something arousing about the circumstances you find yourselves in, or (as mentioned) you close your eyes and let your imagination take hold. It's complicated, and there's more than one dimension.