Victorian student priest Paul Pavlou made a seemingly kind offer of respite when his best friend was dying of cancer and his wife worked three jobs to support their six children.

But Pavlou used the opportunity to repeatedly rape his dying friend's 12-year-old son.

Paul Pavlou.

Pavlou, now 59, was jailed for 10 years in the County Court on Monday for his 2003 and 2004 crimes, described as "callous to the family's plight".

"[The victim's] family looked to you as a figure of learning, a mentor, and a person who could be trusted implicitly," Judge Greg Lyon said.