This girl on CL answered my ad, first of all she said she wasn't looking for a guy as she just broke up a

2 year relationship and shes not there yet, she said she just missed the company of a guy and thats why she answered my ad. we been emailing since february and met in person, she said i was fun and we'd hang out again . well we did on thursday and while driving her home she said she had a great tim while i was driving she was checking her email ,and by the time we got home she told me her boyfriend was asking where she was? im pissed because she never told me of this and im starting to believe this person is a slime bag. what should i do thanks?