After the end of a relationship with someone, it is still possible to remain emotionally connected to the person. Another possibility is wanting to keep an eye on what she's been doing. Perhaps you find yourself in a cycle of breaking up and coming back or still hoping for reconciliation or staying in your ex's life. In either case, it can be helpful to try to decipher whether your ex moved on and fell in love with someone else or not. Fortunately, there are several telltale signs.
Steps
Method 1 of 3: Perceiving Changes in Communication

Step 1. Notice if he ignores your calls
When you call your ex, note if he answers or drops voicemail. If he's always ignoring calls (and especially if this behavior is new), it could be a sign that someone else is in sight.
- Wait to see if he ignores your calls three times in a row or more.
- Don't forget to call only every day or so.

Step 2. Acknowledge no replies to text messages
If you text your ex and don't get a reply (or just reply after a day), it could be that he's liking someone. He may even be with the person (or have been out of the night) when he receives the message, and that's why he doesn't respond.
- As with calls, try to wait until he replies by texting at least three times before jumping to conclusions.
- Again, be sure to give yourself time before you send the next message so you don't overwhelm your ex.

Step 3. See if he never starts a conversation
If your ex answers text messages and answers the phone, but never initiates any kind of communication, this could be a sign that he is in love with someone else. The attitude may show that he still wants to be polite but has no natural and apparent interest in talking to you.
- Try to stop your attempts to stay in touch for a while (say a week).
- Notice whether he steps up to talk to you or not.

Step 4. Check if he deleted your friendship on social networks
If you go to your ex's Facebook, Twitter, or Instagram page and find that you are no longer on his or her friends list, that could be a negative sign. He may have excluded you because he doesn't want you to see the change in relationship status or pictures of him with the new love.
- If he has privacy on the pages, the deletion is immediately noticeable.
- Directly check his friends list if the profile is public.

Step 5. Find out if he changed his phone number
A far more dramatic action your ex can take (and a much clearer sign) is to change the phone number. If you try to get in touch with him and find his cell phone changed without warning, chances are your ex has fallen in love with someone else.
Ask your friends about changing the number. If there is a good explanation for this exchange, a mutual friend may be able to provide clues
Method 2 of 3: Looking for Changes in Behavior

Step 1. Assess whether or not he responds to flirting
If your ex has always reciprocated about your flirting and has suddenly changed his attitude, this could indicate that he is wasting energy flirting with a new love.
- Try flirting with him as usual (but don't overdo it) and gauge your ex's reaction.
- See if this happens more than once before drawing conclusions.

Step 2. Feel if he is far away
One sign that your ex has gotten over you is sudden distance. If he doesn't share more details of his life, doesn't ask for more support from you and doesn't want to be physically close anymore, it could be that he is in love with someone else.
Try to find out if there is something that is bothering you and making you stay away

Step 3. Find out if he cancels plans with you
If you've been making plans with your ex for a while and he suddenly starts canceling them, it could be a sign that he's hooking up with someone else. One cancellation might mean nothing, but several in a row might be a bad sign.

Step 4. Pay attention to the time he makes available to you
If you used to rely on your ex for company, support, or just to catch up, but all of a sudden he stopped having time for you, it could be that he is in a new relationship. It's hard to make time for you if he's been spending the whole day with his new love.
- Also notice if he asks for some kind of attention and support at times, but never gives back when you need it.
- This attitude can also indicate that he has started a new relationship but still turns to you in times of loneliness (which shows a character flaw).

Step 5. Notice if he has stopped being affectionate with you
If you and your ex have continued with a “colorful friendship” since the official break up and he suddenly stopped with that side of the relationship, that's a pretty clear sign that someone else is filling that space. If he has found another love, he will probably cut you off.
If he refuses your advances, ask directly what has changed
Method 3 of 3: Looking for external clues

Step 1. Beware of public displays of affection
If you happen to see your ex being affectionate with someone else in public, that's pretty solid evidence that he's moving on. The fact that he is comfortable enough to take such an attitude already shows that he may be liking someone.
- Public displays of affection go beyond a simple kiss. When witnessing your ex with someone else, pay attention to their body language.
- Are they touching? Are they too close to each other?

Step 2. Talk to mutual friends
Take rumors seriously when you hear that your ex is with someone else. You may be tempted to ignore or disbelieve these rumors, but remember that gossip often has a bit of truth.
- Ask a few people if you are suspicious.
- Consider asking your ex directly.

Step 3. Listen to what he has to say
Believe him if your ex says he's breaking up with you directly. Try to accept and leave the relationship behind if he explains that he has fallen in love with someone else.

Step 4. See if there is any change in Facebook relationship status
If you are still friends on the social network, note the change in relationship status. The status “in a serious relationship” is a very clear message that he is with someone new. Even a vague change like “in a complicated relationship” could mean he's fallen in love with someone.
- Also keep an eye out for romantic photos on Facebook.
- Another idea is to pay attention to posts with romantic sayings.

Step 5. Ask yourself if it's time to end the relationship for good
Instead of wasting time crying over your ex and playing detective to find out if he's seeing someone or not, consider talking openly about it. Honestly think about whether the two of you have a future together, and if it seems like you don't, direct your energy toward getting on with your life.