The good thing in everything you've said is that both of you share a good bond, and this recent addition of colleagues has caused some tiff, so firstly talking clearly and openly about the whole thing is essential and will help get clarity too. Friendship is necessary for both of you, and generally, friendships involve a lot, depending on the gender of friends. So the conversation about the friendship and friends will help. If things don't start getting better or fall in place, get help from a professional, to better understand the whole thing also to strike a balance between plans with friends and with one another.

Introspection is required.you know what is bothering you.connecg with psychologist to resolve inner conflicts

What is my hunch that you are feeling jealousy and anxiety both . Ask yourself what does it mean if they share adult jokes etc ? Does it mean, I am unloveable or loss of relationship or any other thing .there can be endless possibilities so you need  tailor made counseling session instead of chat base suggestion.

I understand how you're feeling, and it's completely normal to have concerns about your husband's new friendships. It's essential to talk openly and kindly with him about your worries. Let him know that you're feeling a bit uneasy about how close he is with his female colleague and the jokes they share. Listen to his side of the story too. Find out how he sees things and why this friendship is important to him. It's all about finding a balance that works for both of you. You could also suggest spending more quality time together to strengthen your connection. If things continue to bother you, consider seeking the help of a counselor or therapist. They can provide guidance and support to navigate this issue and strengthen your relationship. Ultimately, trust is the foundation of any relationship, so assure him that you trust him and believe in your love. It's about understanding each other and finding a solution that makes you both feel secure and loved.