The pair - who exposed their relationship on Twitter after posting multiple pictures of themselves kissing - have yet to sleep together after being hurt by former partners.
"We're both a bit damaged," Norcross told Reveal. "I'm usually a really romantic guy, but I haven't done it so much with Jodie.
"I've had it thrown in my face by other girls one too many times, so I'm wary now."
Marsh added: "I think, in a way, we've both been ruined by other people. I know he's not pushing the boat out massively with me, but I'm not with him either."
The glamour model-turned-bodybuilder recently claimed not to have had sex for a year and suggested that she would happily date women again.
For photographs and an exclusive behind-the-scenes video of Marsh and Norcross visit the Reveal website. The full interview is also available in this week's Reveal magazine - out now.