Calum Best is so desperate to get his on/off relationship with Lindsay Lohan back on track that he has reportedly pledged to seek help for his addictions if she takes him back.

Spurred on by Lindsay�s own efforts at sobriety, Calum is said to have promised to enroll in daily therapy sessions at a secret Malibu location in a bid to prove he�s serious about their relationship.

A source tells the Daily Star: �Calum first had the idea at Lindsay�s 21st birthday when he was watching her being so strong and staying away from alcohol.

�He still drinks � but obviously can�t do that around her anymore. And the way he feels at the moment, by her side is the only place he wants to be.�

If he does make it to rehab, Calum�s therapists are going to have a tough job on their hands since he has admitted to addictions to drugs, booze, sex and, of course, party-crazed starlets.