Ex Boybriends Weighing Heavy on my Mind!?

I have been dating my girlfriend for about 8 months and we get along very
well. We both love each other and talk about moving in together. I am
experiencing some problems with my girlfriend and her friendships with her
ex boyfriends. She has had three relationships in the last four years with
boyfriends that have all lived with her at some point. She has broken up with
them but continues to talk to them/text and in one case sees an ex bf on a
weekly basis. Two of these ex bf's she has had relationships with on and off
several times in the last four years.

My girlfriend says that they are just friends and I am trying to be comfortable
with that but here is what is happening and I would like some feedback on if
this is acceptable?
Her one ex bf talks to her sometimes 3-4 times a day. He lives within walking
distance to her house and they both have dogs and take them for walks
together one to three times a week. In the summer they go to a couple of dog
parks which can take up to two hours to go and come back. He still has a key
to her house and she calls on him to let her dogs out often while she is at
work. When they were dating last, she was at one point pregnant with his
baby but lost it due to a misscarriage.
My girlfriend maintains that they are just friends but the frequency of their
communication and getting together is starting to weigh heavy on my
thoughts.
I have expressed to her that this bothers me from time to time. One time she
said she called him up and told him that they need to cut back their
interaction but they seem to fall back into a comfort zone with calling each
other several times a day.
My girfriend has another ex bf that sometimes calls at 6:00 A.M. She says
that is when they can talk before he goes to work.
I am looking forward to your thoughts?

She's cheating on you.

she is cheating on you for sure... i use to be friends with my ex bf, we were together for 5yrs anyway i got a new bf and i cheated on his with ex more than once... i now realised that you CANNOT be friend with any ex without there being feeling involved and I'm talking more than just friend feelings.. if i were you i would just move on from this mess and tell her that you cant be with a girl who still hasnt leartn to let go of past relationships. they dont have a kid together so there should be nothing keeping them from parting ways. if she argues this with you and wont give them up then she is def cheating on you. this will teach you to go out with girls who stay friend wth ex bf.

be careful, she is chitting on u. there is nothing else btn the two other than love or last! think twise..........

m8,book a time slot now,for when it do,nt work out,the mornings are booked solid the afternoons are pretty busy just where do you fit in,she sounds like a very cool person but as they say,you can keep some of the people happy some of the time but you cant keep all of the people happy all of the time.ask who she wants to keep happy.