The "Ex" Factor. What do you think?

My boyfriend thinks it is cool to keep in contact with his ex girlfriends. namely, his first love (boring) anyway, when they chat, they start to reflect on the intimate details of their past and how they would never let go of each other and have tons of babies if they were together next "lifetime". He mentioned to her that he always thought she was the one for him etc. And a bunch of other things that should not be brought up if it is just innocent ex talk. He tells her to show better pics of her self on her webpage ( I guesss he wants to remember her in her better days) I just think this is too close for comfort. Oh yes and never once did he mention me. we were togther for 6 years, she knows about me, but he does not mention me in their convo.What do you think? too intimate or am I overreacting? I told him i would never be friends with an ex because I would not want to make my current BF uncomfortable. Granted, I have spoke to an ex, but it was strictly DULL. no reminiscing at all.