Couples should talk about how much they're comfortable sharing with other people so that there are no secrets.
Maynooth Counselling and Psychotherapy Therapist Helen Vaughan said being open and honest is the best approach for partners, so any so-called micro-cheating doesn't bleed into something bigger.
Micro-cheating is not a full-blown affair, but can take the form of engaging in interactions that teeter around the edges of intimacy.
Ms Vaughan told Newstalk Breakfast it's not necessarily physical.
"It's when you have an emotional connection with somebody else, so it mightn't be a physical cheat," she said.
"When you're sharing details of your inner world with somebody else, or when there's ongoing contact with someone who's not your partner - talking about life, talking about work.
"When it gets secret and when it's lies, that's when it bleeds into cheating.
"The problem, though is that different people have different expectations and have different beliefs around what's right and what's wrong.
"You might think it's cheating and I might think it's not."
'Different needs'
Ms Vaughan said the easiest thing to do is to be open about what you expect.
"I guess it's about each person having a conversation with their partner about what they expect of them, and what they expect of themselves," she said.
"Different relationships might have different needs and different boundaries.
"It's about knowing what your partner considers OK and not OK, and whether you're OK with that.
"When you do something outside of that, and if you're keeping it secret, then there's a big red flag.
"If you're flirting with somebody else, and it's giving you something, I would ask questions about why do you need that in your life?
"Why are you not getting it in your relationship? Does it point to something being wrong in the relationship and do we need to work on that?"
'There's a problem'
Ms Vaughan said instances where the partner doesn't know about the micro-cheating is where it becomes a problem.
"If you're keeping something secret from your partner because you know they won't like it, to me there's a problem then," she said.
"Usually that couple will end up in front of me trying to sort out whatever's going on.
"If there's secrecy and lies then something's not right.
"It's up to you to communicate with your partner and figure out what you're OK with and what you're not," she added.
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