Lindsay Lohan as The Sister nun licking gun

Sister act. Lindsay Lohan in the provocative new "Machete" movie poster. Photo: Splash News

How do you solve a problem like Lindsay Lohan?

Beats us. But while the starlet may be staring down the barrel of a 90-day jail sentence, a poster for her new film sees her as a nun (really) licking said barrel.

Where's Mother Superior when you need her?

The revolver tonsil hockey is all to promote "Machete," a new Robert Rodriguez film which casts Lohan as "The Sister," who we can only assume is one very naughty nun.

According to Moviefone, Robert De Niro, Jessica Alba, Danny Trejo, and Steven Seagal (!) also star in the action flick. If seeing Lohan French kiss a gun doesn't have you intrigued, surely that line-up will?

Meanwhile, check out Lohan's controversial courtroom nail art.