Pair spotted out together at film screening
The couple have been dating for several months, but have kept the relationship under wraps as a mark of respect to Michelle‘s late fiancé Heath Ledger, who died of an accidental overdose in January aged 28.
She began dating Spike, 37, in the summer.
‘[Spike] couldn’t seem to keep his hands off her,’ an onlooker tells People. ‘It was very cute.’
Michelle, 28, has a 3-year-old daughter Matilda from her relationship with Heath.