Whether you’re 19 or 35, there’s one hard and fast rule that every girl should stick to; never waste your precious time dating the wrong man.

Of course, this is much easier said than done. When your antennae are on high alert, how is it even possible to know whether the new and shiny object of your affections is a hero or a zero? Between the rush of oxytocin you get from your first hook-up, the euphoria of early dates and the novelty of wearing matching underwear, our brains are truly scrambled. I’ve lost count the number of times friends have said, “I’ll play this one by ear”, even though the man in question has served up a massive dealbreaker on the first date. Conversely, I’ve seen others fold at the table and throw away perfectly lovely men over a minor issue – the colour of his socks or some such – that can be easily remedied. You get the gist; it’s a hugely confusing time.

So, in this great poker game of love, when should you stay… and when should you walk away? There may be no set rules, but we’ve tried our best to divide the relationship dealbreakers into the ones that can be overcome, and the true-blue, red-card offences.

Stay if:

He’s lost his job

It’s hardly an ideal scenario, but not an entirely unusual one these days. If your man loses his job due to something like redundancy, this is sadly out of his control. Pay attention to his post-redundancy behaviour; is he back out looking for a job, or has he developed a huge fondness for Jeremy Kyle? “When my boyfriend got fired, he was devastated and took to the sofa for a few weeks,” notes Jennifer, 28. “I had the fear he’d turn into some sort of slob who’d never go back to work, but after a while he got bored with sitting at home. Unfortunately, he hasn’t found a job yet, but he’s enrolled in a computer course to give him more options. I’m so proud of him for at least being proactive with his time. And I know he’ll get a job he really loves eventually.”

He snores

So what if the quality of your sleep diminishes? Snoring is easily sorted. Go to the chemist and buy some over-the-counter remedies, sleep in the guest room… or if it’s really unbearable talk to him about undergoing a minor surgical procedure on his adenoids.

He mentions his unusual sex fantasies to you

Within every relationship, each person has a right to float their various sexual fantasies. No doubt he’s hoping to go on a great sexual odyssey with you as his new partner, so take it as a compliment. No one is asking you to do anything you don’t want to, so a simple ‘yes’ or ‘no’ will do the trick.

He’s a bit lacking in the trouser department

Short of surgery, there’s precious little one can do about a small penis. If it’s getting in the way of a good time, switch positions (doggy style is best in this situation), and help him brush up on his bedroom technique.

You don’t get on with his mum/friends

“My boyfriend’s mum and I got off on the wrong foot,” explains Lisa, 29. “It was completely tense going round to his parents’ house, but once she saw that Ciaran and I were in it for the long haul, she began to soften up. Our son Liam was born 18 months ago, and all the rifts and tensions disappeared pretty much overnight.”

You argue a lot

Many people throw in the towel after a series of heated rows; remember though, you can change the way you row, so that insults aren’t being traded. Once you know how to have a constructive argument, and you figure out the root cause of all those blow-ups, you’ll be able to move forward.

He flirts a lot

No one likes to be on a night out with their man while he works the room. First things first; tell him that you don’t appreciate it when he gives other girls the glad eye. If he doesn’t respond well to the accusation, beat him at his own game. If he brings up your own flirting, remind him that this is what you must go through when he does the same. It shouldn’t be long before a truce is called.

He leaves wet towels on the floor

Having to housebreak a new man is no fun, but within a few months, he should be well trained. “My man had never lived with anyone except his parents before, so he did treat our flat like a hotel,” says Síle, 29. “It was nothing a roster on the fridge couldn’t sort out, though.”

He isn’t really your type

So, he may be shorter/fairer/nerdier/EMO-er than you’re accustomed to, but big swinging mickey. Put it this way; dating your type hasn’t worked for you in the past, so this could be your perfect time to change tactics. Remember, fortune favours the brave… and a stack of Topman vouchers favours the sartorially challenged.

He likes Jedward

It may sound like a sackable offence, but maybe he just hasn’t been exposed to the right sort of music. Give him a crash course in good music/TV/films and see where you stand. Live and let live and all that.

Walk away if:

He’s violent

Even if he’s not directing those fists of fury at you, any sort of violence is inexcusable. “At an Interpol concert, my ex throttled a guy who jumped on me in the crowd,” recalls Serena, 31. “At the time I thought he was my knight in shining armour… until he chucked a glass ashtray towards my head during a drunken row. It was a near-miss for him, and for me.”

He’s hot, but you can’t have a conversation

Tempting though it may be to enjoy some arm candy – as is every girl’s right – you often need to share the wealth and release the dim-but-pretty types back into the dating pool. In time, the prettiness will fade (as you start to notice his bland personality). Plus, as we know, the really good-looking ones can often be trouble, creating insecurity in even the most self-assured of girlfriends.

He’s never around on Friday/Saturday nights

Either he’s ashamed to be seen with you on ‘prime-time’ nights, or you’re so low down on his priority list that he has made plans without you. Always be wary of a man who can’t – or won’t – see you on Date Night, that’s all I’m saying.

He’s possessive

“I had a boyfriend who was so oddly possessive that he’d come out on girly nights and cramp my style,” recalls Chrissy, 25. “He also hated me having male platonic friends, even if they were gay. My friends were too polite to say anything. Then one day, he followed me out to my parents’ house – he said he’d lost our house key – and it dawned on me that he didn’t trust me at all. Knowing that, it was never going to work out.”

He talks about your friend a lot

We’re not implying that he’s with you in a bid to get closer to your pal, but be wary of a man who has any girl on his mind that’s not you. Aside from sounding completely stupid, the guy who fixates on your friend is also showing a remarkable lack of respect. Definitely a sackable offence.

You’re getting nothing but red flags

Because many of us just want to be in a nice relationship, we’re divils for turning our backs on the many sirens going off in our heads. Swearing that you’ll deal with any upsets somewhere down the line, you delve further and further into something that clearly isn’t for you. Your instincts are there for a reason, so pay attention to them and respect what they’re trying to tell you.

He doesn’t want what you want in life

You’re broody; he’s allergic to babies. He’s eyeing up a move to Canada, and you can’t bear to leave your family for more than two weeks. If your life plans don’t tally up, all the will in the world won’t keep you together. Only you can say whether it’s worth compromising your big dreams of children, travel or marriage for any man. But more often than not, it isn’t.

He criticises you

“My ex would wait until we were in the pub, and in front of my friends, to slag off my clothes or jewellery,” says Alannah, 33. “It seemed harmless enough until he started to criticise everything all the time, from my cooking down to the way I made the bed! The rot had sort of set in, and there was no real way back from it.”

You pay for everything

Again, this is a dynamic that’s hard to undo once it’s been set. I once had a boyfriend who would feign embarrassment and pat around in his pockets whenever a bill would arrive in a bar or restaurant. Months later, he’d actually push the dinner bill towards me. It was humiliating for me, emasculating for him, and the relationship imploded because there was no sense of ‘partnership’ there.

He’s cheated on you

Infidelity is a thorny issue, and is probably best treated on a case-by-case basis. If, however, he’s been caught (ie, he didn’t confess), he doesn’t seem contrite, or you know the other person involved, it’s almost certainly time to give the pig the heave-ho. With the right amount of care and attention, some relationships can withstand the fierce blow of infidelity. Sad to say, they’re the exception and not the rule.