I dont think youre paranoid no. In fact in my opinion you are right to be concerned. I'm not suggesting there is anything going on but if it were me I would feel I was betraying my husband if I was communicating with other males so much especially if it were an ex. I would discuss it with her and tell her how you feel without accusing her of anything. Like someone else said would she like it if it were the other way round? There should be no need to do what shes doing, she should be talking to you more and not be stuck on FB.