Whether it's a red flag or not largely depends on the context and dynamics of your girlfriend's relationship with her baby daddy, as well as your own feelings and expectations in the relationship.
Here are a few things to consider:
Co-parenting: If they have a child together, it's natural for them to communicate regularly to discuss matters related to their child's well-being, schedules, and other parenting responsibilities. This kind of communication is generally healthy and necessary for effective co-parenting.
Boundaries: While co-parents need to communicate about their child, it's essential for them to maintain appropriate boundaries. If they seem to be excessively socializing or laughing about unrelated matters, it might raise concerns about their relationship.
Trust: Trust is crucial in any relationship. If you trust your girlfriend and believe that their communication is solely about the child, it may not be a red flag. However, if you have reasons to doubt her honesty or fidelity, it's essential to address those concerns openly and honestly.
Communication: Talk to your girlfriend about your feelings and concerns. It's essential to have open and honest communication in a relationship. Share how their constant communication makes you feel and try to understand her perspective as well.
Past history: Consider their history as co-parents and their relationship before you came into the picture. If they were close friends before or had a complicated romantic history, it could influence their current interactions.
Your feelings: Trust your instincts and emotions. If something feels off to you, it's worth addressing and discussing with your girlfriend.
Remember, every relationship is unique, and what might be a red flag in one situation might not be the same in another. The key is to have open communication, trust, and understanding with your partner. If you're struggling with your emotions or concerns, you might consider seeking support from a professional counselor or therapist to help you navigate these complex feelings and relationships.