Complex sentence: Luke's best mate Darren then made a move on Mandy but they fizzled out as a couple, then Mandy began dating Ben Davies, Luke realised he was still in love with her but was too ashamed to tell her the truth.
Split into simpler sentences: Luke's best mate Darren then makes a move on Mandy but they soon after end their relationship. Luke realises he is still in love with her but is too ashamed to tell her the truth.