I Have Been With Him For 5 Years, No Sign Of Marriage - Family

Hi Famlanders, Please I need your advice. I beg you all to save a sister. I have to bring this here coz I know it's where I will get wonderful contributions. Again, I am using this new account coz I have friends and customers here. I don't want to blow my cover. Please this is real and not fiction. This will be quite lengthy, please bear with me. 

I met this guy in 2013 when I was in year one. It was not a steady relationship coz we barely call nor see so I didn't take him serious. And whenever we see, it was always at one friends house or another. I accused him of being married but he vehemently denied it. Later on I figured out he had accommodation issue after he lost his job. He later rented a house when he got another job with one of our prestigious federal universities here in Nigeria and that was when things became serious (kinda). 

We became very serious around 2016 that is why I count it as 5 years instead of 7. But then during one of my visits, I was sleeping in the room when I overheard him talking to someone but the only thing that caught my attention was when he said "I don't even have a girlfriend". Though I didn't confront him, but I thought about it deeply.