Want to know what men are really thinking when they don't return a text, friend you on Facebook or introduce you to a friend?

Seth Meyers, our expert on all things love related and the author of Dr. Seth's Love Prescription: Overcome Relationship Repetition Syndrome and Find the Love You Deserve (Adams Media Corporation, 2010), is here to help us decode what men's actions really mean – and if it's time to cut them loose.

1. He texts you sporadically
To put it bluntly, "He is not interested in you, but likes the attention from you," says Dr. Meyers.

Other interpretations include: "He is interested, but doesn't want to commit to you or he isn't interested, but feels guilty that he doesn't like you, so he makes occasional gestures to remind himself that he's a nice guy," Dr. Meyers explains.

Invest your time in someone who makes you a priority in his life, not an option. Your time is more valuable than that.

2. He won't confirm you as a friend on Facebook
According to Dr. Meyers there are two possibilities in this situation: "Either he's not a big Facebook user or he doesn't want you to know what he's up to."

If it's the latter, ask yourself why your guy might not want you to know what he's up to. Have you questioned him in the past about his Facebook activity? Have you fought about other people writing on his wall and what their intentions were?

Perhaps avoiding you on Facebook is a way for him to try to prevent an argument. If you find it shady, let him know. Communicate with him openly about how you feel.

3. He doesn't introduce you to a friend during a chance encounter
There is nothing worse than walking down the street hand in hand with your other half, only for him to drop your hand when he runs into someone he knows and not bother to introduce you.

"This is a huge red flag," says Dr. Meyers. "If the guy you're dating ever does this, it's time to end the relationship – unless he has an incredibly good excuse."

One of the only acceptable excuses for not introducing you is if he forgot the person's name and didn't want to embarrass himself.

4. He locks his cellphone
Before you jump to conclusions, Dr. Meyers thinks it's important to note that locking your cellphone is normal behaviour these days.

"It could mean that he has been burned before when someone invaded his privacy or it could mean that he is hiding something – but in most cases, it just means that he likes his privacy and it has nothing to do with how honest or dishonest he is," says Dr. Meyers.

Don't read too much into this behaviour. If, however, your guy always goes into another room to use the phone when you're around or if he pulls his phone away from your gaze while texting, you may have something to be concerned about. Your mate deserves his privacy, but he shouldn't be secretive or trying to hide things from you.

5. He doesn't say he's with you when a friend calls and asks him what he's up to
"This omission is usually a reflection of shady, secretive behaviour," warns Dr. Meyers. "Unless the person he's talking to is someone he dislikes and he doesn't want to share any details of his personal life, this behaviour usually indicates secrecy – and secrecy is poison for any romantic relationship."

If this is a common occurrence, call him on it the next time it happens. Ask him why he didn't mention you and let him know how it makes you feel. Perhaps it's just an oversight and by bringing it to his attention you can both ensure it doesn't happen again.

Remember, all situations will differ. The important thing is to trust your intuition. If you feel as though you're being strung along, hidden or mistreated by your guy, you likely are. Check in with yourself to see what you're willing to put up with.