My boyfriend might be biologically my cousin.

My (18) boyfriend (18) and I have been together for almost two years. Things are going great in the relationship and we are seriously considering going long-distance which would start this fall. So we thought maybe before that we should get to know our families better. My boyfriends mom and dad have been married for over 20 years and so have my parents.<br><br>So we decided that I should get to know my boyfriends family better first. My boyfriend is a little apprehensive about it and I really dont know why but he said that it's not that he doesn't want to introduce me but that he doesn't want to find out something about himself. I tried to get an answer out of him but he wouldn't budge. I talked to my mom about it and she said that it's probably that his mom who was born in 1978 had an affair in the 90s.<br><br>I talked to my boyfriends mom about it and I tried to get an answer out of her but she wouldn't budge. I told her about what my mom said and she said that I shouldn't listen to my mom and that she is just jealous of their family.<br><br>So I got really curious and took the initiative to do an ancestryDNA test which came back today and lo and behold, my boyfriend and I are 3.8% compatible DNA wise. According to the test, this makes us 3rd cousins.<br><br>Now, I don't care that much about it but I feel lied to and betrayed. I feel like I have the right to know and I want to know why she lied to me and where this 3.8% came from.<br><br>How do I confront her about it without making the situation awkward and making my boyfriend and his family hate me for good?<br><br>&#x200B;