ok for the last 4 months i have been dating this girl, and its been going extremely well but just like every relationship theres a problem,
besides her living 3 hours away i still see her almost every weekend(she comes home from college) but my job
has me working nights and most of the time i work weekends too, so basiclly i only see here until like 10pm and then i have to leave, then she goes out.....and sometimes doesnt come home till the next day
now im not a jelous guy and we have a very trusting relationship but while im at work i get calls from her telling me how much fun im missing out on tells me these parties are great, but heres what gets me, she always goes to parties with one guy all the time, she tells me that hes just a friend and that hes hopelessly in love with her, plus shes always re-assured me that she had never cheated on anyone and that i have nothing to worry about. but she has a problem when she gets drunk, when im not out with her, she flirts heavily with everyone guys and girls(although the girls dont bother me

) i wouldnt be so worried but the worst feeling is i feel like i cant do anything about it.
i would love to call in sick and go with her to these parties but im a my probabtional period at my job for 3 more months so calling in sick is almost out of the question
so what im asking for is advice, what can i do? should i be more worried that i am?