(1) There are so many reasons that a person lies. But you know, trust
is the basic element in every love story. If you want to know the
reason, you should ask him directly.
(2) It may not be
truth as he like to lie you.
(3) He want to hide
some real stories from you.
(4) yes, I think it
is right. Many guys do not like to talk their ex-love. Each love
story should be separated.
(5) You feel sad as
you love him. So, you do not want him to lie you.
actually, I do not like people to lie me. And certainly, I think
it is not acceptable if my boyfriend lies me again and again. In
his mind, he may think you are stupid and should believe his lie.
Anyway, if you still love him, talk to him about what you feel.