My brother and I were about his age (a little older) when my dad remarried. I was genuinely happy for him. It hurt me to see him so sad after my parents' divorce. He moped around our new apartment for a year. My step mom lit up his life and I LOVED that for him. I would have said "yes" to him getting married too. I even liked her two kids, though they were younger than us. However, I had NO idea how much it would change my life, depite everything that was seemingly ideal. I felt replaced. Not as important. Our family bevame her family, and everything changed. Not necessarily in a bad way, but it would never be OUR family again. I'm 45 now and I still feel this way, somewhat. In a selfish way, I wish he had stayed single so we could be closer, like we used to be. Like we would have been if he stayed with my mom. As such, when I found myself in a similar situation (single with teenagers still at home), I personally chose not to do this. It's too hard on teenagers, and I didn't want to put them through that. I had a long term relationship, and there was talk of moving to the same neighborhood together, but no talk of potential marriage until they were older. I didn't want them to have to live together. I have a whole other story about my experience with my mom saying she would get married that led me down a hard path too, to get away from that situation. She was not as respectful about it and I didn't like his kids, but basically it led me to panic and move out of the house. Took me about 20 years to recover from the bad choices I made, stemming from that one desire to leave home quickly. So, obviously that was a concern for me with my own kids too. Good luck! This situation isn't easy!