I think my man is cheating on me. Should I end it with this serial liar?

Photo: Courtesy

I have been with my boyfriend for five months and throughout our relationship, he has constantly been lying to me. He lies about everything. I have suspected for a long time that he lies about his out of town trips and I recently found out that he lied to me about being out of the country. When I confronted him about it, he lied even some more. He only admitted to lying after his friend confirmed to me that he was with him during the time he was supposed to be out of the country. When I confronted him again, he came clean and claimed that he had been really stressed and he just needed some time alone. I feel really hurt and confused. I don't understand why he could not just tell me to give him some space. I am starting to suspect that he is cheating even though he vehemently denied it when I asked him about it. I hate being lied to because it makes me feel stupid. Is his dishonesty enough reason to end the relationship? Dora.

Dear Dora,