Have you ever questioned your partner's fidelity? You may have found yourself harbouring a sense of suspicion but, unless you've caught them red-handed, how else can you confirm they're doing the dirty on you?

After a Reddit user posed the question: "What are some signs your partner has cheated on you?" fellow Redditors were quick to share what they believe are the ultimate telltale signs of a cheat.

Here are 18 signs you might be dating a dud:

1. "They start accusing you of cheating."


2. "They get accusatory of almost anything, not just cheating. Cheaters do this because it helps them feel less guilty."

3. "They start texting more (and more privately) when you're together and seem to be in a better mood after checking their phone."

4. "When they demand to go through your phone but throw a crying fit when you want to go through theirs."

5. "They suddenly have lots more things to do in the evenings/weekends which means they can't see you."

6. "They have more mood swings, so one moment [they are] super lovey with you, next day [they are] super grumpy at you."

7. "Beyond mood, signs could be buying new underwear or sexy clothes, caring about what they wear again, maybe getting a new haircut, scent or changing something they've never cared about before."

8. "Excuses/absences go up - this one tends to be obvious. If they're working late more often, go on more lunches, don't answer their phone like they used to etc. There's probably a reason."

9."Sometimes they'll withdraw from you, no more sex, no more intimacy - either it'll stop all together or it gets rare/done mechanically. They don't want to 'cheat' on their new partner."

10. "The desire to bring up his/her name. It's like showing they try to prove their innocence by how unconcerned they are by that person. So they'll generally start naming them more often. Same thing for specific night out, locations, etc, but easiest to spot with names."

11. "If you ask where they've been and they have an answer that's just a little too detailed."

12. "The desired type of affection changes. Again for no visible reason. It means there is an invisible reason. If he's always on about anal and suddenly fine just cuddling, there's a reason."

13. "When 'Domino's' texts at 2am and it's to send nudes."

14. "There's always one person - some third party - who knows the significant other is cheating, whether it's a good friend or someone they work with. You'll notice that the third party treats you differently."

15. "A drastic change of behavior. It's much easier to tell when you live with the other person. If they go from always wanting to stay home together to going places without you on a normal basis, that's a big sign."

16. "Suddenly the dates on the weekend become earlier than usual or end sooner, because a second date is planned for the same night."

17. "They are offended and hostile that you suspect it."

18. "Sadly they often are (temporarily) much happier and have a renewed lust for life. Infatuation is a heady drug."