How can i overcome this insecurity?

[jennnn :)]

so, me and my boyfriend have been dating for 8 months now.
i lost my trust on him when i found out that he still says 'i love you'
to his ex girlfriend but we were able to fix things that time. we're
often happy, we rarely fight. but this insecurity overcomes on me
cause we were talking on twitter today. he got this tweet-limit thing
so, he had to talk through DMs (direct message) it's more private
than replies cause no one else can see your conversation than
you and the person you're talking to. turned out that he was talking
to his ex girlfriend and then his ex girlfriend tweeted.. "I wanna
re-live our happy moments together" then, my boyfriend tweeted..
"I guess I'm not in the mood to tweet.. idk why" :| this thought came
over me and i felt like they still like each other and he might be cheating
behind my back. advices? please.

[Champagne N]

Ok, why is he even still talking to his ex? Do they have kids together? If not, I would seriously reevaluate everything this man is telling you. If there is no reason for communication between the two of them then there's no reason why they should still be communicating. This is why making friends with exes does not work. I would suggest preparing yourself emotionally to move on. I know it's not easy because he's probably a really sweet guy on the surface, but honestly if the ex is STILL not out of the picture in the first eight months of your relationship, it is time to move on.

[Miss I dunno]

its understandable that your insecure about this issue
but i really don't think it's you being insecure
i feel that this guy is obviously playing around with you
just confront him, there no harm in doing this, save the twitter message and print it out and show him and just talk civilly