When your ex begins dating, it can be difficult on your child, especially if your son hopes that someday you and your ex will get back together. You can ease your son’s discomfort, as well as help him build a friendship with his father’s girlfriend, by talking with him about his fears, talking to your ex about your son's concerns and acting cordially around the new girlfriend.
Your Son’s Concerns
Keep in mind that your son might worry about how his dad’s new girlfriend will affect his time with his father and about the possibility of becoming part of a blended family, according to the HelpGuide.org article, “Guide to Step-Parenting & Blended Families.” Acknowledge that you are his only mom and that’s it’s OK for him to like his father's girlfriend without betraying his love for you. You might also remind your son that his father will still love him even if his dad develops strong feelings for his new girlfriend, suggests Carl E. Pickhardt, Ph.D., writing for the Psychology Today website. Tell your son that it's going to take time for him to get to know and like his dad's new girlfriend and that he should treat her with respect, no matter how he feels.
Building a Relationship
If your son is elementary age or older, ask if he and the new girlfriend have any common interests that they could do together. If your son doesn’t know of any shared interests, suggest that he ask his father or the girlfriend what she likes to do. If he is kindergarten age or younger, ask his dad to choose activities that your son and the girlfriend could do together that both will enjoy, such as playing games or going somewhere fun together.
Talking with Your Ex
Share your son's fears with your ex privately. You might gently suggest that your ex talk to his son about the relationship. If your son hasn’t yet met the girlfriend, suggest that they do so in a group setting over a casual event, such as a picnic or an evening of miniature golf, so your son has time to get to know the girlfriend in a friendly, casual setting. Encourage your ex to let his girlfriend know that your son is apprehensive. Suggest that he provide her with information about your son’s interests so that she can help them find commonalities.
Model Appropriate Behavior
Ask to meet your ex’s girlfriend and get to know her. You don’t have to be bosom buddies, but it might help your son feel more comfortable if he sees you acting friendly toward the girlfriend. Shake hands and treat her respectfully to be a good role model for how your son should treat her. Encourage your son to give her a chance.