Confused about everything

I've been with my boyfriend or should I say the guy I'm dating for the last year in a half, he has been out of town for the last couple of days and last night he said that I've always been his side chick and I was like wtf excuse me and he said yea you know you e always been my side chick but then he laughed so today I was looking thu his fb friends list and I came along a girls page with pic of them including a wedding picture so now I'm totally confused like wtf has he been married this whole time & I was too stupid to know so now my question is. Should I ask him about it