Can or should I ask my significant other to stop talking and to not associate with his ex? If so, how?

Try asking him nicely to stop talking to her/him. If that doesnt work, i say let him do his own thing. You can't stop someone from talking to someone they wanna talk to.

In my personal experience, I’ve found that sitting down with your significant other and explaining to them why you wish they would stop talking to their ex is very helpful. Depending upon your reason, maybe it makes you uncomfortable because they used to be so close? Determining the root of your unease will make it easier to explain to your partner and help you make a better case.

Let your significant other know how you feel about it. Don't demand anything, just say "hey this makes me feel uncomfortable", nobody likes feeling compared. Your significant other should understand.

That's understandable if that's something you'd want, considering your s.o once loved this person and obviously still has a connection if they're talking to their ex. I believe just bringing it up bluntly and telling them how you feel about them talking to their ex, and how it affects/hurts you is the best way to go about it.

If you are worried that your significant other has feelings for his ex or will develop them, you should talk about this with them. I would explain how you feel and see how they feel about it, too.

If you don’t trust your partner talking to his ex then speak up about it. You have every right to ask him or discuss it with him. Approach it by telling him how it makes you feel. Be honest and if he really does care about your feelings then he will do whatever to make you happy. Talking about it with him will give you peace of mind and reassurance.

If contact with their Ex has an impact on your feelings, it's important to express that to your significant other. Be respectful in your approach. Once you have been understood, you will know based on their actions what you truly mean to them. Exes are exes for a reason.

Relationships with ex-girlfriends and boyfriends can be polarizing issues in relationships; however, many exes have shared a long history with their partners and do indeed develop a friendship after a break-up. Like any issue in a relationship, the partners need to talk honestly about this, and examine whether an ongoing relationship with an ex is appropriate and/or healthy. If it is, there's no reason for concern. If there are residual feelings or longings, then it would likely not be conducive to a good relationship. Honest communication and trust is key.

So the other person is the one you love. Right? Love is a feeling of freedom and not boundation. If you love someone, let them be free of choices. Conversations are a way out always. Open up more. The way out is know the other person's problems. Know what makes the other person go out. Spend more time together. Let the other person choose the right one. Let the love flow inside out. The feelings are the only things which cannot be kept hidden for so long. Don't bind the other with choices. Rather make them feel the love you hold for the other. Things wills settle themselves.

Can you ask your significant other to stop talking to their ex? Yes. Should you? Well.... Probably not unless the ex is slashing your tires or threatening to harm you. Just like you need freedom to pick and choose your friends based on the qualities you value, so does your significant other. Am I saying there is not a problem when your significant other talks to his ex? Nope. Not at all. If you are getting bothered by it, it is clearly impacting your feelings. And that is a problem no matter what. And that shouldn't be ignored. Is it possessiveness? Like mine mine mine. If so, what is the fear associated with this? Is this a matter of trust? Maybe your significant other has violated that trust or you feel is likely to violate your trust? Maybe you need to work together to reestablish that trust? Maybe you need to reevaluate being with that partner if the cannot operate in a way that honours the trust you extended? If none of those are the case, then you need to reflect inwards in yourself, and ask yourself what's making you feel insecure (as in, not feeling secure about the relationship)? Really looking at these questions will tell you a lot about the work and improvement that needs to be done. It will be something you need to work on for yourself, something you need to work on as a couple, or a bit of both. And really that is all you have the power to control. And while the ex might be the trigger of the feelings. They aren't the problem (unless they are slashing tires, or threatening harm. In which case yes ask your partner to stop seeing their ex and call the authorities promptly).