His instincts told him to move on, but he stayed loyal—that’s heroic

When a woman falls in love with a man, she follows her own biological path—meaning her love and her interests are aligned.
When a man falls in love with a woman, he goes against his biological path—meaning his love and his interests are at odds.
His interests told him to let go of exclusivity, yet he held on. Tell me, isn't that noble?