Jessica and Amber say when their mother married Steve, a hard-working religious man, they thought they had won the stepdad lottery. But behind closed doors, these sisters claim their new father preyed on them.

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“It used to always start off, like, if you were doing feet rubs,” Jessica recalls of the abuse she claims she endured from ages 9-16. “Then he would slowly start moving his hand up towards our private area.”

Amber, who claims Steve started abusing her when she was 6, says he would almost make a game of it, saying, “Let’s tingle each other.”

WATCH: Sisters Claim Stepdad Would Use ‘Tickling Game’ As An Excuse To ‘Touch Us’

She explains, “Almost like getting chills, like if someone’s rubbing up and down your arms, your legs, you kind of get like goose bumpy, and he would call it ‘tingling.’”

Steve was convicted of sexual abuse after taking a plea deal pursuant to which he did not have to admit wrongdoing and had to register as a sex offender, but he maintains his innocence.

WATCH: Man Claims Stepdaughters Lied ‘To Put Me In Jail’

In the video above, hear more from Jessica and Amber, including how they claim Steve dressed to expose himself. And on Monday’s episode of Dr. Phil, hear from Steve and why he claims his ex-wife brainwashed the girls to lie about being abused. And, Steve agrees to take a polygraph exam. On Tuesday, see what his results reveal. Check here to see where you can watch.

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