How would you feel??

If your new bf told you he had 2 girlfriends one "high school girlfriend for 2 years" and another "girlfriend for 3 years", but later found out the high school girlfriend was really a 9 year long relationship and then still had some on and off contact after and shortly before the two of you met.  Would you be insecure?  Also I found a paper of his boss referring to a "proposal..."  But later goes on to say the relationship ended.  My bf swears he just asked his boss to write that and that he never proposed to anyone.  I feel like he's lying.. 😔 a little insecure over here.