OK, Emma.... here are the definitions:
Lust - • noun 1 strong sexual desire. 2 a passionate desire for something. 3 Theology a sensuous appetite regarded as sinful.
• verb (usu. lust for/after) feel lust for someone or something.
Love - • noun 1 an intense feeling of deep affection. 2 a deep romantic attachment to someone. 3 a great interest and pleasure in something. 4 a person or thing that one loves.
• verb 1 feel love for. 2 like very much. 3 loving showing love or great care.
OK? The "shag", no matter how good or bad it is, has nothing to do with love