So Valentine's Day might not seem like the best time to bring up cheating - but it's always better to be safe than sorry.
Extramarital dating site Victoria Milan asked its members what the big signs to look out for are when someone is cheating.
The site’s CEO said it “takes one to know one,” so cheaters are best placed to pinpoint the behaviours that could get them caught out, according to Her.
And according to them, here are the top ten behaviours to look out for:
1. Being particularly careful with privacy, for example, with their phone and computer
2. Acting distant and avoiding eye contact
3. Taking extra care with their appearance
4. Not behaving naturally: Not being concerned about family matters appearing distracted
5. Showering at strange hours or putting clothes directly in the laundry
6. Having contradicting alibis
7. Being more loving than normal
8. Having lipstick marks or perfume on their clothes
9. Making excuses to not have sex
10. Keeping bills or invoices of dates secret